1-[2-(AMINOMETHYL)BENZYL]-2-THIOXO-1,2,3,5-TETRAHYDRO-4H-PYRROLO[3,2-d]PYRIMIDIN-4-ONES AS INHIBITORS OF MYELOPEROXIDASE

ABSTRACT

and pharmaceutically acceptable salts thereof, together with compositions containing them and their use in therapy. The compounds are inhibitors of the enzyme MPO and are thereby particularly useful in the treatment or prophylaxis of cardiovascular disorders such as heart failure and coronary artery disease related conditions.

TECHNICAL FIELD

The technical field relates to certain1-[2-(aminomethyl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-onecompounds of formula (I), to their use in the treatment of amyeloperoxidase related disease or condition, for example heart failureand coronary artery disease related conditions, and to pharmaceuticalcompositions containing them.

BACKGROUND

Myeloperoxidase (MPO) is a heme-containing enzyme found in neutrophilicgranulocytes (neutrophils) and monocytes. MPO is one member of a diverseprotein family of mammalian peroxidases that also includes eosinophilperoxidase (EPO), thyroid peroxidase (TPO), salivary peroxidase (SPS),lactoperoxidase (LPO), prostaglandin H synthase (PGHS), and others. Themature enzyme is a dimer of identical halves. Each half moleculecontains a covalently bound heme that exhibits unusual spectralproperties responsible for the characteristic green color of MPO.Cleavage of the disulphide bridge linking the two halves of MPO yieldsthe hemi-enzyme that exhibits spectral and catalytic propertiesindistinguishable from those of the intact enzyme. The enzyme isactivated by hydrogen peroxide, the source of which can be superoxidedismuatase (SOD)-catalyzed NADPH-derived superoxide anion and xanthineoxidase-derived superoxide anion and hydrogen peroxide formed uponpurine oxidation. The main physiological substrates of MPO are halides(e.g. chloride) and pseudohalides (like thiocyanate), formingmicrobicidal hypohalous acids like hypochlorous acid (bleach) andhypothiocyanous acid (J. Clin. Biochem. Nutr., 2011, 48, 8-19).

Neutrophils play an important microbicidal role by phagocytosing(engulfing) and killing microorganisms. The engulfed load isincorporated into vacuoles, termed phagosomes, which fuse with granulescontaining myeloperoxidase to form phagolysosomes. In phagolysosomes theenzymatic activity of the myeloperoxidase leads to the formation ofhypochlorous acid, a potent bactericidal compound (Free Radical Biology& Medicine, 2010, 49, 1834-1845). Hypochlorous acid is oxidizing initself, and reacts most avidly with thiols and thioethers, but alsoconverts amines into chloramines, and chlorinates aromatic amino acids.

MPO can also be released to the outside of the cells where the reactionwith chloride can induce damage to adjacent tissue. In addition to thiscontrolled release of MPO, neutrophils can also cast webs of decondensedDNA interspersed with intracellular proteins such as MPO into theextracellular space, so called neutrophil extracellular traps (NET).These NETs are thought to play a role in host defence towardsextracellular microbes and has also been suggested to be an importantpathophysiological mechanism in acute inflammatory diseases such as theimmunothrombosis occurring in sepsis (Nature Rev. Immunol, 2013, 13, 34)and in autoimmunity, such as in systemic lupus erythematousus (SLE) (J.Immunol., 2011, 187, 538-552). Notably, MPO is required for NETformation (Blood, 2011, 117, 953).

Systemic levels of MPO is a well-described risk factor for variouscardiovascular diseases (e.g. heart failure, acute coronary syndrome,myocardial infarction, stable coronary artery disease andatherosclerosis related conditions (Circulation, 2003, 108, 1440-1445;N. Engl. J. Med., 2003, 349, 1595-604; J. Am. Coll. Cardiol., 2007, 49,2364-70). The role of MPO in these morbidities is not only related tothe oxidative damage caused by the enzymatic products, but also a due toa consumption of nitric oxide, an important regulator of vascular andcardiomyocyte relaxation. Importantly, the contribution of MPO tocardiovascular diseases is not only via infiltration of neutrophils andmonocytes into the vasculature and the myocardium, but also via thestrategic deposition of extracellular MPO on proteoglycans on thebasolateral side of the endothelium (Science, 2002, 296, 2391).

A causative role of MPO for the development of cardiovascular disease isalso supported by the lower cardiovascular morbidity in MPO-defectivesubjects (Acta Haematol., 2000, 104, 10-15) and reduced coronary flowreserve (J. Biomed. Sci., 2004, 11, 59-64) and increased mortality insubjects carrying a gain-of-function mutation in the MPO-promotor (NewEngl. J. Med., 2004, 350, 517; Free Rad. Biol. & Med., 2009, 47, 1584;J. Biol. Chem., 1996, 271, 14412-14420). A direct effect on vascularflow and relaxation was also observed after administration of MPO inpigs (Eur. Heart J., 2011, 33, 1625).

Linkage of MPO activity to diseases has thus been implicated incardiovascular diseases with microvascular inflammation and reactivefibrosis including heart failure such as heart failure with preservedejection fraction, heart failure with reduced ejection fraction, acutecoronary syndrome, myocardial infarction, stable coronary artery diseaseand atherosclerosis related conditions.

Although considerable progress has been made in the understanding andtreatment of heart failure (HF), morbidity and mortality due to HFremain high. The main cause of cardiac remodeling, which underlies HFdevelopment, is increased ventricular wall stress as a result ofsustained hypertension, myocardial infarction, valvular insufficiency orother events. Cardiac remodeling is referred to as any change in cardiacstructure, dimension, mass or function and, although it is initially acompensatory mechanism to maintain cardiac output it may result indecompensation and HF development (J. Am. Coll. Cardiol., 2000, 35,569-582). Main processes that contribute to cardiac remodeling arecardiomyocyte hypertrophy (growth), fibrosis and inflammation (Nat. Rev.Mol. Cell. Biol., 2006, 7, 589-600; Circ. Res., 2010, 106, 47-57).

Currently, the cornerstone of HF treatment is based on reduction ofventricular wall stress and it consists mainly on the use of inhibitorsof the renin-angiotensin-aldosterone systems, such asangiotensin-converting enzyme-inhibitors (ACE-I), of β-adrenergicblockers and of diuretics (Eur. Heart J., 2012, 14, 803-869). Despitetreatment, HF mortality is still high and about 50% of all patients diewithin 5 years after first diagnosis (J. Am. Coll. Cardiol., 1999, 33,734-742). New treatment options directly focused at the major molecularand cellular processes driving cardiac remodeling are therefore urgentlyneeded. Heart failure can be sub-divided in HF with reduced ejectionfraction (HFrEF) and with preserved ejection fraction (HFpEF) (Curr.Heart Fail. Rep., 2012, 9, 363-368). HFrEF and HFpEF differ with regardto pathophysiology, clinical characteristics and treatment. HFrEF isoften referred to as systolic HF and treatment with ACE inhibitors,β-blockers and diuretics have successfully reduced mortality andmorbidity rates in patients with HFrEF. In contrast, for HFpEF, which isoften denoted as diastolic HF, no treatment has to date convincinglyshown to reduce mortality or morbidity. This is alarming, since theincidence and prevalence of HFpEF is rising, both in absolute terms andrelative to HFrEF (Eur. Heart J., 2013, 34, 1424-1431). A keycharacteristic of HFpEF is reduced contractility and relaxation of theventricular wall. Cardiac fibrosis is an important contributor of thisstiffening of the ventricular wall. Targeting cardiac fibrosis istherefore an potential therapeutic strategy for HFpEF patients, but alsoin HFrEF patients fibrosis plays an important role. Moreover, HFpEF maytransit into cardiac dilatation and into HFrEF. It will therefore beimportant to investigate whether pharmacological targeting of cardiacfibrosis could halt or attenuate HFpEF and its potential transition intoHFrEF. Microvascular inflammation, resulting in interstitial fibrosisappears to play an important role in HFpEF development (J. Am. Coll.Cardiol., 2013, 62, 263-271) and an association has been demonstratedbetween HF and the inflammatory enzyme, myeloperoxidase (MPO) (J. Am.Coll. Cardiol., 2007, 49, 2364-2370). In terms of fibrosis, there aredata suggesting that the MPO-product hypochlorous acid (HOCl), is animportant regulatory switch modulating extracellular matrix proteins,including metalloproteinases (MMPs) (J. Biol. Chem., 2001, 276,41279-41287; J. Biol. Chem., 2003, 278, 28403-28409). This is alsosupported by the attenuation of angiotensin II-induced atrial fibrosisand reduced MMP-activity observed in MPO-deficient. Moreover, additionof recombinant MPO to Mpo−/− mice resulted in atrial fibrosis indicatingthat increased MPO activity is sufficient for induction of fibrosis(Nat. Med., 2010, 16, 470-474). In a post-myocardial infarct (MI) modelMpo−/− mice also showed diminished ventricular remodeling and improvedfunction (J. Exp. Med., 2003, 197, 615-624). Together these resultsindicate that MPO activity is a key player for structural remodeling ofthe myocardium under pathological conditions.

Pharmacological inhibition of MPO activity could attenuate cardiacfibrosis and preserve cardiac function under conditions that may trigger(diastolic) HFpEF and (systolic) HFrEF. In particular stiffening of theheart as a result of extensive fibrosis could be prevented and maypreserve cardiac function.

There is a need for an orally active inhibitor of MPO for the treatmentof e.g. heart failure and coronary artery disease related conditions. Inorder to increase the therapeutic index of such a medication, it isnecessary to obtain an MPO inhibitor being selective for MPO over otherperoxidases such as for instance TPO to reduce the risk of thyroidrelated adverse events. It is considered that a high selectivity for MPOover TPO may reduce the risk of a growth of the thyroid gland (Pharm.Res., 2013, 30, 1513-24. Furthermore, it is desirable that an MPOinhibitor for the use in cardiovascular therapy would have limited bloodbrain barrier penetrating properties as to minimize its effect in thecentral nervous system (CNS).

WO2003/089430, WO2005/037835, WO2007/120097, WO2007/120098 andWO2007/142576 disclose thioxantine derivatives and the use thereof asMPO inhibitors in therapy.

WO2006/062465 and WO2007/142577 disclose2-thioxo-1,2,3,4-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one derivativesclaimed to be inhibitors of MPO. It is stated that the compounds mayshow selectivity against related enzymes such as TPO.

WO2009/025618 discloses thioxantine and2-thioxo-1,2,3,4-tetrahydro-pyrrolo[3,2-d]pyrimidin-4-one derivativesand the use of MPO inhibitors for the treatment of multiple systematrophy (MSA) and Huntington's disease (HD) and for neuroprotection.

J. Labelled Compounds and Radiopharmaceuticals, 2012, 55, 393-399,discloses some tritiated, ¹³C and ¹⁴C labeled thioxantine derivatives aswell as a ¹⁴C labeled pyrrolo[3,2-d]pyrimidin-4-one compound. Thecompounds are stated to be inactivators of MPO.

J. Biol. Chem., 2011, 286, 37578-37589, discloses certain thioxantinederivatives. The compounds are stated to inhibit MPO in plasma anddecrease protein chlorination in a mouse model. The compounds are alsoclaimed to be poor inhibitors of TPO.

WO2013/068875 discloses thiopyrimidone derivatives claimed to be MPOinhibitors.

An object is to provide novel MPO inhibitors useful in therapy. Afurther object is to provide novel compounds having improved selectivityfor the MPO enzyme over the TPO enzyme and/or having limited blood brainbarrier penetrating properties.

SUMMARY

There is provided a compound of formula (I).

whereinR¹ is H, F, Cl or CF₃,R² is H, CH₃ or C₂H₅, andR³ is H, CH₃, C₂H₅, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl,tert-butyl, cyclopropyl, cyclopropylmethyl, cyclobutyl, cyclobutylmethylor cyclopentyl,or a pharmaceutically acceptable salt thereof.

The compounds of formula (I) are MPO inhibitors. Thus, the compounds offormula (I) may be used as a medicament, in particular for disorders,diseases or conditions responsive to inhibition of MPO, and morespecifically cardiovascular conditions, including coronary arterydisease, heart failure (HF), heart failure with reduced ejectionfraction (HFrEF) and heart failure with preserved ejection fraction(HFpEF), in which MPO plays a role.

It is to be understood that when the absolute configuration (R or S) ofa single enantiomer of the compounds disclosed herein is specified inthe present specification, it is the carbon atom to which R² is attachedthat is the stereocenter (chiral center) in question.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the loading values of MPO-related biomarkers for predictionof symptomatic severity of HFpEF patients (NYHA class). For clarity, theloading values of the remaining variables (n=240) have been omitted inthe figure. To put the shown loading values in perspective of theremainder of the data, the maximal and minimal loading values in thedataset are indicated by dotted lines. The black bar representing theloading value for NT-proBNP is shown for comparison.

FIG. 2 shows the dose-dependent reduction of uric acid by theMPO-inhibitor AZD3241 in Healthy Volunteers. Subjects received placeboor the indicated daily dose for 10 days, and the difference in plasmaurate levels versus baseline was calculated. Each symbol represents onesubject.

FIG. 3 shows that activated MPO drives the production of urate in vitro.Activated MPO was incubated with xanthine and titrated amounts ofExample 3:1-{2-[(1R)-1-aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-onefor 80 min, after which urate levels were quantified by LC-MS. Thedotted line represents the urate formed in the presence of unactivatedMPO.

FIG. 4 shows the X-ray powder diffraction pattern for Example 3(j):1-{2-[(1R)-1-aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one.

FIG. 5 shows the X-ray powder diffraction pattern for Example 7:1-[2-(Aminomethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one.

DETAILED DESCRIPTION

For the avoidance of doubt it is to be understood that where in thisspecification a group is qualified by “defined above” the said groupencompasses the first occurring and broadest definition as well as eachand all of the other definitions for that group.

In one aspect, there are provided compounds of formula (I), orpharmaceutically acceptable salts thereof, wherein R¹ represents H, F,Cl or CF₃.

In a further embodiment, R¹ represents Cl.

In one embodiment, R² represents H, CH₃ or C₂H₅.

In a further embodiment, R² represents CH₃ or C₂H₅.

In still a further embodiment, R² represents CH₃.

In one embodiment, R³ represents H, CH₃, C₂H₅, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl,cyclopropylmethyl, cyclobutyl, cyclobutylmethyl or cyclopentyl.

In a further embodiment, R³ represents H.

In still a further embodiment, the carbon atom to which R² is attachedhas the R-configuration when R² represents CH₃ or C₂H₅.

In one embodiment the compound of formula (I) is selected from:

-   1-{2-[(1R)-1-aminopropyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[2-(1-aminoethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{2-[(1R)-1-aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{2-[(1S)-1-aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{4-chloro-2-[1-(methylamino)ethyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{4-chloro-2-[(ethylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[2-(aminomethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{4-chloro-2-[(methylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(2-{[(cyclobutylmethyl)amino]methyl}benzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{2-[(cyclobutylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{2-[(cyclopentylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-(2-{[(2-methylpropyl)amino]methyl}benzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{2-[(propan-2-ylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-[2-(aminomethyl)-4-(trifluoromethyl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;-   1-{2-[(methylamino)methyl]-4-(trifluoromethyl)benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one;    and-   pharmaceutically acceptable salts thereof.

It shall be noted that any one of these specific compounds may bedisclaimed from any of the herein mentioned embodiments.

In one embodiment there is provided a process for the preparation ofcompounds of formula (I) or pharmaceutically acceptable salts ofcompounds of formula (I), and the intermediates used in the preparationthereof.

Another embodiment is a product obtainable by any of the processes orexamples disclosed herein.

Further, because of the fact that the absolute configuration of theenantiomers of the compounds disclosed herein was determined by aspectroscopy study, rather than by for instance an X-ray study (seeworking Example 3(b)), it is to be understood that the R and Sdesignation will be reversed should the results from said spectroscopicstudy for one reason or another be proven wrong.

Medical and Pharmaceutical Use

The compounds of formula (I) and their pharmaceutically acceptable saltsare useful because they possess pharmacological activity as inhibitorsof the enzyme MPO.

The compounds of formula (I) and their pharmaceutically acceptable saltsare indicated for use in the treatment or prophylaxis of diseases orconditions in which modulation of the activity of the enzymemyeloperoxidase (MPO) is desirable. In particular, linkage of MPOactivity to disease has been implicated in cardiovascular diseases.Therefore the disclosed compounds are particularly indicated for use inthe treatment of coronary artery disease and heart failure conditions ordisorders in mammals including man. Further, the disclosed compounds areparticularly indicated for use in the treatment of chronic kidneydisease (CKD), cardiorenal syndrome (CRS), non-alcoholic steatohepatitis(NASH) and arrhythmia conditions or disorders in mammals including man.

Conditions or disorders that may be specifically mentioned includecoronary artery disease, acute coronary syndrome, heart failure, heartfailure with reduced ejection fraction and heart failure with preservedejection fraction.

Prophylaxis is expected to be particularly relevant to the treatment ofpersons who have suffered a previous episode of, or are otherwiseconsidered to be at increased risk of, the disease or condition inquestion. Persons at risk of developing a particular disease orcondition generally include those having a family history of the diseaseor condition, or those who have been identified by genetic testing orscreening or identified through specific biomarker pattern to beparticularly susceptible to developing the disease or condition.

For the above-mentioned therapeutic indications, the dosage administeredwill, of course, vary with the compound employed, the mode ofadministration and the treatment desired. However, in general,satisfactory results are obtained when the compounds are administered ata dosage of the solid form of between 1 mg and 2000 mg per day.

The compounds of formula (I), and pharmaceutically acceptablederivatives thereof, may be used on their own, or in the form ofappropriate pharmaceutical compositions in which the compound orderivative is in admixture with a pharmaceutically acceptable adjuvant,diluent or carrier. Thus, another aspect concerns a pharmaceuticalcomposition comprising a novel compound of formula (I), or apharmaceutically acceptable salt thereof, in admixture with apharmaceutically acceptable adjuvant, diluent or carrier. Administrationmay be by, but is not limited to, enteral (including oral, sublingual orrectal), intranasal, inhalation, intravenous, topical or otherparenteral routes. Conventional procedures for the selection andpreparation of suitable pharmaceutical formulations are described in,for example, Pharmaceuticals—The Science of Dosage Form Designs, M. E.Aulton, Churchill Livingstone, 2^(nd) Ed. 2002. The pharmaceuticalcomposition preferably comprises less than 80% and more preferably lessthan 50% of a compound of formula (I), or a pharmaceutically acceptablesalt thereof.

In one embodiment there is provided a compound of formula (I), or apharmaceutically acceptable salt of a compound of formula (I), for usein therapy, especially in the prevention or treatment of cardiovasculardisease in a mammal, particularly a human.

In a further embodiment there is provided a compound of formula (I), ora pharmaceutically acceptable salt of a compound of formula (I), for usein therapy, especially in the prevention or treatment of a conditionwhere inhibition of MPO would be beneficial.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment ofcoronary artery disease in a mammal, particularly a human.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment of acutecoronary syndrome in a mammal, particularly a human.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment of heartfailure in a mammal, particularly a human.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment of heartfailure with reduced ejection fraction in a mammal, particularly ahuman.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment of heartfailure with preserved ejection fraction in a mammal, particularly ahuman.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment of CKD ina mammal, particularly a human.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment of CRS ina mammal, particularly a human.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment of NASH ina mammal, particularly a human.

In still a further embodiment there is provided a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),for use in therapy, especially in the prevention or treatment ofarrhythmia in a mammal, particularly a human.

In one embodiment there is provided a method of treating, or reducingthe risk of, diseases or conditions in which inhibition of the enzymeMPO is beneficial which comprises administering to a person sufferingfrom or at risk of, said disease or condition, a therapeuticallyeffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt thereof.

In a further embodiment there is provided a method of treating, orreducing the risk of, cardiovascular disorders, in a person sufferingfrom or at risk of, said disease or condition, wherein the methodcomprises administering to the person a therapeutically effective amountof a compound of formula (I), or a pharmaceutically acceptable saltthereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, coronary artery disease, in a person sufferingfrom or at risk of, said disease or condition, wherein the methodcomprises administering to the person a therapeutically effective amountof a compound of formula (I), or a pharmaceutically acceptable saltthereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, acute coronary syndrome, in a person sufferingfrom or at risk of, said disease or condition, wherein the methodcomprises administering to the person a therapeutically effective amountof a compound of formula (I), or a pharmaceutically acceptable saltthereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, heart failure, in a person suffering from or atrisk of, said disease or condition, wherein the method comprisesadministering to the person a therapeutically effective amount of acompound of formula (I), or a pharmaceutically acceptable salt thereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, heart failure with reduced ejection fraction, in aperson suffering from or at risk of, said disease or condition, whereinthe method comprises administering to the person a therapeuticallyeffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt thereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, heart failure with preserved ejection fraction, ina person suffering from or at risk of, said disease or condition,wherein the method comprises administering to the person atherapeutically effective amount of a compound of formula (I), or apharmaceutically acceptable salt thereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, CKD, in a person suffering from or at risk of,said disease or condition, wherein the method comprises administering tothe person a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, CRS, in a person suffering from or at risk of,said disease or condition, wherein the method comprises administering tothe person a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, NASH, in a person suffering from or at risk of,said disease or condition, wherein the method comprises administering tothe person a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt thereof.

In still a further embodiment there is provided a method of treating, orreducing the risk of, arrhythmia, in a person suffering from or at riskof, said disease or condition, wherein the method comprisesadministering to the person a therapeutically effective amount of acompound of formula (I), or a pharmaceutically acceptable salt thereof.

In one embodiment there is provided a pharmaceutical formulationcomprising a therapeutically effective amount of a compound of formula(I), or a pharmaceutically acceptable salt of a compound of formula (I),and a pharmaceutically acceptable diluent, excipient and/or inertcarrier.

In a further embodiment there is provided a pharmaceutical formulationcomprising a compound of formula (I), or a pharmaceutically acceptablesalt of a compound of formula (I), in admixture with a pharmaceuticallyacceptable adjuvant, diluent or carrier, for use in therapy, especiallyin the prevention or treatment of a condition where inhibition of MPOwould be beneficial.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of coronary arterydisease in a mammal, particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of acute coronarysyndrome in a mammal, particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of heart failure in amammal, particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of heart failure withreduced ejection fraction in a mammal, particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of heart failure withpreserved ejection fraction in a mammal, particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of CKD in a mammal,particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of CRS in a mammal,particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of NASH in a mammal,particularly a human.

In still a further embodiment there is provided a pharmaceuticalformulation comprising a compound of formula (I), or a pharmaceuticallyacceptable salt of a compound of formula (I), in admixture with apharmaceutically acceptable adjuvant, diluent or carrier, for use intherapy, especially in the prevention or treatment of arrhythmia in amammal, particularly a human.

There is also provided a process for the preparation of such apharmaceutical composition which comprises mixing the ingredients.

In one embodiment, plasma urate levels may be used as a stratifying tooland a pharmacodynamic biomarker for MPO inhibitor treatment.

To contextualize MPO into HFpEF pathophysiology, a set of MPO-relatedbiomarkers were quantified in plasma from HFpEF patients, i.e. the KaRencohort (Eur. J. Heart Failure, 2009, 11, 198-204). The cohort representspatients diagnosed with HFpEF that were followed up for events 18 monthsafter inclusion of the study. In addition to ECG and echocardiographydata at inclusion, the registry also includes data on medication,medical history and clinical chemistry data. In addition to levels ofMPO and the activity thereof, the following biomarkers were quantified(mechanistic rationale/link within parenthesis): calprotectin,lipocalin-2 (NGAL), sTNFR1 (neutrophil/monocyte involvement), arginine(Arg), asymmetric (ADMA) and symmetric (SDMA) dimethyl arginine,endothelin-1 (vascular health); urate and allantoin (purine catabolismand oxidative tone), TIMP-1, TIMP-4 and osteopontin (tissueremodelling).

A supervised principal component analysis—orthogonal projection tolatent structures by partial least square analysis (OPLS)—were performedto identify and rank variables (n=256) explaining the symptomaticseverity of the disease (NYHA score (The Criteria Committee of the NewYork Heart Association. Nomenclature and Criteria for the Diagnosis ofDiseases of the Heart and Great Vessels. 9th ed. Boston, Mass.: Little,Brown & Co; 1994: 253-256)). The KaRen registry dataset were merged withthe MPO-related biomarker data obtained from plasma drawn at studyinclusion of the patient. All data were scaled to unit variance and meancentered. In addition, variables with a max/mean-ratio >10, werelog-transformed to increase equal leverage of all variables. Thisgenerated a data matrix consisting of 257 variables in 86 patients thatwas subjected to principal component analysis using Simca 13 (Umetrics,Umeå, Sweden). In the OPLS analysis, variables (loadings) contributingto the predicted response, in this case NYHA score, can be separatedfrom loadings varying independently of the response, hence orthogonalvariables. The informative variables can in turn be either positively ornegatively correlating to the response. The higher the magnitude of theloading value (either positive or negative), the better the correlationto the predicted response. The OPLS model predicting NYHA scoreexplained 50% (R2Y=0.50) of the variation of NYHA score, with a Q2 valueof 0.26 after a full Jack knife cross validation as implemented in theSIMCA software.

As indicated by the amplitude of the loading values shown in FIG. 1, themajority of the MPO-related biomarkers were good predictors of the NYHAscore, arguing that these biomarkers represent active participation inthe pathophysiology, and not merely act as bystanders (as would havebeen suggested by close-to-zero loading values). Interestingly, allbiomarkers but osteopontin, Arg, and ADMA performed better than didNT-proBNP in predicting NYHA score.

The co-clustering of the MPO-related biomarkers with urate and itsoxidation product allantoin (also corroborated by significantcorrelation between urate and all of the individual biomarkers whenanalyzed in a univariate fashion, Table 1) suggests that urate may infact be a biomarker for inflammation and tissue hypoxia due to poorvascular function.

We postulate that tissue hypoxia, the degree of which will be determinedby the degree of inflammation and vascular function, has impact onplasma urate concentration. Myocardial ischemia results in acceleratedloss of ATP and a corresponding buildup of urate levels in rat hearts(Am. J. Physiol. Heart Circ. Physiol., 2004, 286, H677-H684; J. Biol.Chem., 1995, 270, 18797-18803). Furthermore, increased myocardialproduction of urate contributes to systemic urate levels and correlatesto NYHA class in heart failure patients (Circ. J., 2006, 70, 1006-1011).

Myeloperoxidase deposited in the vascular wall (J. Clin. Invest., 2001,108, 1759-1770) has been shown to drive vascular dysfunction both inhealthy (Eur. Heart J., 2012, 33, 1625-1634) and in diseased individuals(Circulation, 2004, 110, 1134-1139; Circulation, 2006, 113, 1871-1878).We therefore suggest that myeloperoxidase inhibition will result inimproved vascular function (as supported by data from MPO-deficienthumans, Eur. Heart J., 2012, 33, 1625-1634), which will improve tissueperfusion and oxygen supply and thereby decrease local production andthus systemic concentrations of urate. This hypothesis is also supportedby data from clinical trials using two distinct myeloperoxidaseinhibitors (AZD5904(http://openinnovation.astrazeneca.com/what-we-offer/compound/azd5904/?_sm_au=isH0QK1bJkWQtMf7)and AZD3241 (Nuclear Medicine and Biology, 2015, 42, 555-560), both ofwhich dose-dependently reduced urate levels in healthy objects (datashown for AZD3241 in FIG. 2 (ClinicalTrials.gov Identifier:NCT00914303).

In addition to MPOs role in maintaining elevated urate levels due topoor perfusion as discussed above, we also propose that MPO per se maygenerate urate by oxidizing xanthine in concert with xanthine oxidase.This occurs when activated MPO encounters xanthine in vitro, and theincreased urate production can be concentration-dependently inhibited byExample 3 (FIG. 3).

In a further embodiment, plasma urate level may be used as a stratifyingtool and a pharmacodynamic biomarker for MPO inhibitor treatment incombination with other biomarkers or clinical characteristics toidentify patients with poor vascular function (and thus highinflammatory tone according to OPLS analysis above).

In still a further embodiment, there is provided a method of identifyingpatients suitable for MPO inhibitor treatment encompassing themeasurement of plasma urate levels.

The compounds of formula (I) herein exemplified, when tested in an MPObinding assay, for example Test A described below, preferably with anIC₅₀ less than 50 μM. The compounds of formula (I) also display apromising pharmacological profiles by separating desired and undesiredeffects in vivo.

These and other embodiments are described in greater detail hereinbelow, where further aspects will be apparent to one skilled in the artfrom reading this specification.

Pharmacological Properties

The compounds of formula (I) or pharmaceutically acceptable saltsthereof are believed to be useful in the prevention or treatment ofcardiovascular conditions, including but not limited to coronary arterydisease, acute coronary syndrome, heart failure, heart failure withreduced ejection fraction and heart failure with preserved ejectionfraction in a mammal, particularly a human.

For the avoidance of doubt, as used herein, the term “treatment”includes therapeutic and/or prophylactic treatment.

When a compound or salt described herein is administered as therapy fortreating a disorder, a “therapeutically effective amount” is an amountsufficient to reduce or completely alleviate symptoms or otherdetrimental effects of the disorder, cure the disorder, reverse,completely stop, or slow the progress of the disorder or reduce the riskof the disorder getting worse.

The compounds described herein are thus indicated both in thetherapeutic and/or prophylactic treatment of these conditions.

The compounds described herein have the advantage that they may be moreefficacious, be less toxic, be more selective, be more potent, producefewer side effects, be more easily absorbed, and/or have a betterpharmacokinetic profile (e.g. higher oral bioavailability and/or lowerclearance), than compounds known in the prior art.

Combination Therapy

The compounds of formula (I), or a pharmaceutically acceptable saltthereof, may also be administered in conjunction with other compoundsused for the treatment of the above conditions.

In another embodiment, there is a combination therapy wherein a compoundof formula (I), or a pharmaceutically acceptable salt thereof, and asecond active ingredient are administered concurrently, sequentially orin admixture, for the treatment of one or more of the conditions listedabove. Such a combination may be used in combination with one or morefurther active ingredients.

Compounds described herein may be of use in treating cardiovascular,metabolic and renal disease in combination with agents that are

-   -   cardiac therapies,    -   anti-hypertensives,    -   diuretics,    -   peripheral vasodilators,    -   lipid modifying agents,    -   anti-diabetic,    -   anti-inflammatory, or    -   anti-coagulant.

Examples of the above include, but are not restricted to, digitalisglycosides, anti-arrhythmics, calcium channel antagonists, ACEinhibitors, angiotensin receptor blockers (e.g. Valsartan), endothelinreceptor blockers, β-blockers, thiazide diuretics, loop diuretics,cholesterol synthesis inhibitors such as statins (e.g. Rosuvastatin),cholesterol absorption inhibitors, cholesterylester transfer protein(CETP) inhibitors, anti-diabetic drugs such as insulin and analogues,GLP-1 analogues, sulphonamides, dipeptidyl peptidase 4 inhibitors,thiazolidinediones, SGLT-2 inhibitors, and anti-inflammatory drugs suchas NSAID's and CCR2 antagonists, anti-coagulants such as heparins,thrombin inhibitors and inhibitors of factor Xa, platelet aggregationinhibitors, P2X7 antagonists and neprilysin inhibitors (e.g.Sacubitril).

When used in a combination therapy, it is contemplated that thecompounds of formula (I) or pharmaceutically acceptable salts thereofand the other active ingredients may be administered in a singlecomposition, completely separate compositions, or a combination thereof.It also is contemplated that the active ingredients may be administeredconcurrently, simultaneously, sequentially, or separately. Theparticular composition(s) and dosing frequency(ies) of the combinationtherapy will depend on a variety of factors, including, for example, theroute of administration, the condition being treated, the species of thepatient, any potential interactions between the active ingredients whencombined into a single composition, any interactions between the activeingredients when they are administered to the animal patient, andvarious other factors known to physicians (in the context of humanpatients), veterinarians (in the context of non-human patients), andothers skilled in the art.

Pharmaceutical Compositions

There is provided a method of treatment of a condition where inhibitionof MPO is required, which method comprises administration of atherapeutically effective amount of a compound of formula (I) to aperson suffering from, or susceptible to, such a condition.

The compounds of formula (I) will normally be administered via the oral,topical, parenteral, intravenous, intramuscular, subcutaneous or inother injectable ways, buccal, rectal, vaginal, transdermal and/or nasalroute and/or via inhalation, in the form of pharmaceutical preparationscomprising the active ingredient or a pharmaceutically acceptable saltthereof, in a pharmaceutically acceptable dosage form. Depending uponthe disorder and patient to be treated and the route of administration,the compositions may be administered at varying doses. Conventionalprocedures for the selection and preparation of suitable pharmaceuticalformulations are described in, for example, Pharmaceuticals—The Scienceof Dosage Form Designs, M. E. Aulton, Churchill Livingstone, 2^(nd) Ed.2002.

Suitable daily doses of the compounds of formula (I) in therapeuticaltreatment of humans are about 0.0001-100 mg/kg body weight, preferably0.01-10 mg/kg body weight.

Oral formulations are preferred, particularly tablets or capsules whichmay be formulated by methods known to those skilled in the art toprovide doses of the active compound in the range of 0.007 mg to 700 mgfor example 1 mg, 3 mg, 5 mg, 10 mg, 25 mg, 50 mg, 100 mg and 250 mg.

The optimum dosage and frequency of administration will depend on theparticular condition being treated and its severity; the species of thepatient; the age, sex, size and weight, diet, and general physicalcondition of the particular patient; brain/body weight ratio; othermedication the patient may be taking; the route of administration; theformulation; and various other factors known to physicians and othersskilled in the art.

According to a further aspect there is thus provided a pharmaceuticalformulation comprising a compound of formula (I), or pharmaceuticallyacceptable derivatives thereof, in admixture with a pharmaceuticallyacceptable adjuvant, diluent and/or carrier.

The compounds of formula (I) may be present in the pharmaceuticalformulation in a concentration from 0.1 to 99.5%, such as from 0.5 to95%, by weight of the total formulation.

Preparation of the Compounds

In another aspect there is provided a process for preparing a compoundof the formula (I), or a pharmaceutically acceptable salt thereof, whichprocess comprises:

a) reacting a compound of the formula (II) with a compound of theformula (III):

wherein R¹, R² and R³ are as defined in formula (I) and the conditionsare such that a reductive alkylation of the compounds of the formula(III) forms an N—C bond between the nitrogen atom of the compounds offormula (III) and the carbon atom of the aldehyde group, or ketonegroup, of the compounds of formula (II), and where necessary convertingthe resultant compound of formula (I) into a pharmaceutically acceptablesalt thereof, and where desired separating the resultant compound offormula (I) into its individual optical isomers; or

b) reacting a compound of the formula (II), wherein R¹ and R² are asdefined in formula (I), with hydroxylamine or a salt thereof whereuponthe formed oxime intermediate is treated with a reducing agent and theconditions are such that a single bond is formed between the nitrogenatom of the hydroxylamine compound and the carbon atom of the aldehydegroup, or ketone group, of the compounds of formula (II) andsimultaneously the hydroxyl group, which is attached to the nitrogenatom, is replaced by a hydrogen atom, and the obtained primary aminederivative optionally is converted into a secondary amine compound inorder to introduce substituent R³, which is defined in formula (I), by aconventional reductive alkylation process using an appropriate aldehydeor ketone compound and a reducing agent, and where necessary convertingthe resultant compound of formula (I) into a pharmaceutically acceptablesalt thereof, and where desired separating the resultant compound offormula (I) into its individual optical isomers; or

c) treating a compound of the formula (IV) with a deprotection reagent:

wherein R¹ and R² are as defined in formula (I) and PG¹ and PG² areprotecting groups, which may be the same as each other, and the obtainedprimary amine derivative optionally is converted into a secondary aminecompound in order to introduce substituent R³, which is defined informula (I), by a conventional reductive alkylation process using anappropriate aldehyde or ketone compound and a reducing agent, and wherenecessary converting the resultant compound of formula (I) into apharmaceutically acceptable salt thereof, and where desired separatingthe resultant compound of formula (I) into its individual opticalisomers.

The compounds of formula (II) and (III) are reacted with each otherunder conditions of reductive alkylation. The reaction is typicallyperformed at a non-extreme temperature, for example 0-40° C., in asubstantially inert solvent for example N-methylpyrrolidone. Thereaction mixture may also be heated by microwave irradiation at a highertemperature, for instance above 100° C. Typical reducing agents includeborohydrides such as sodium cyanoborohydride. The reduction reaction mayalso be metal-catalysed by the use of such as, for instance,tetraisopropoxytitanium.

The compounds of formula (II) and the hydroxylamine compound are reactedwith each other under conditions of oxime formation followed byreduction. The reaction is typically performed at a non-extremetemperature, for example 20-70° C., in a substantially inert solvent forexample HOAc. Typical reducing agents include metals such as zinc.

The compounds of formula (IV) are reacted with a deprotection reagentunder conventional conditions for removing protecting groups. Typically,the protecting groups are two tert-butyloxycarbonyl groups and typicaldeprotection agents include acids such as hydrogen chloride. Thereaction is typically performed at a temperature of about 30-50° C., inan organic solvent, e.g. MeOH.

The compounds of the formula (II) may be prepared, for example byreacting a compound of formula (V) with benzoyl isothiocyanate:

wherein R¹ and R² are as defined in formula (I) and PG³ and PG⁴ areprotecting groups, which may or may not be the same as each other, and,which may or may not be connected to each other to form a ring. Thereaction conditions are such that a six membered 2-thiopyrimidinone ringis formed, and finally the resultant intermediate is treated with adeprotection reagent in order to remove the protecting groups PG³ andPG⁴ to give a compound of formula (II).

The compounds of the formula (III) are commercially available, known inthe art or may be prepared in conventional manner known by the personskilled in the art.

The compounds of the formula (IV) may be prepared, e.g. by reacting acompound of formula (VI) with benzoyl isothiocyanate:

wherein R¹ and R² are as defined in formula (I) and PG¹ and PG² are asdefined in formula (IV) and the reaction conditions are such that a sixmembered 2-thiopyrimidinone ring is formed to give a compound of formula(IV).

In the cyclization reactions as hereinbefore set forth a compound offormula (V), or a compound of formula (VI), and the benzoylisothiocyanate are slowly added to each other in a suitable organicsolvent, such as MeOH, and stirred until reaction is complete, typicallyat room temperature for between 5 min to 4 h, and if necessary,overnight. Typically a base, such as Cs₂CO₃, is then added and themixture may be stirred at an elevated temperature for a prolonged timesuch as, for instance, at 60° C. for 3-4 h. After reaction is complete,the mixture is usually treated with an acid, such as HOAc, to give therequired compound of formula (II) or of formula (IV).

The compounds of the formula (V) may be prepared, for example byreacting ethyl 3-amino-1H-pyrrole-2-carboxylate with a compound offormula (VII):

wherein R¹ and R² are as defined in formula (I) and PG³ and PG⁴ are asdefined in formula (V) and the reaction conditions are conventionalreductive alkylation conditions. Usually, the amine compound, as ahydrochloride salt, is treated with N,N-diisopropylethylamine and HOAcin an organic solvent e.g. ethanol, and then the aldehyde compound offormula (VII) is added. After the mixture has been stirred for sometime, e.g. at room temperature for 1 h, the reducing agent, such assodium cyanoborohydride, is added and the resultant mixture is stirreduntil the reaction is complete, e.g. at room temperature for 1-20 h, togive the compound of formula (V).

The compounds of the formula (VI) may be prepared, for example byreacting under reductive alkylation conditions ethyl3-amino-1H-pyrrole-2-carboxylate with a compound of formula (VIII):

wherein R¹ and R² are as defined in formula (I) and PG¹ and PG² are asdefined in formula (IV). Usually, the amine compound is introduced as ahydrochloride salt, which then is treated with an excess ofN,N-diisopropylethylamine before the aldehyde compound is added.Preferably, the reducing agent, such as sodium cyanoborohydride, isadded after the mixture of the amino compound and the aldehyde compoundhas been stirred at room temperature for a prolonged time such as e.g.for 18 h. The reaction is typically carried out in an alcohol assolvent, such as MeOH or ethanol, at room temperature and in thepresence of HOAc.

The compounds of the formula (VII) may be prepared as shown in Scheme 1below and by methods analogous to those described in the examples.

Step 1: A compound in accordance with formula (X), wherein R¹, R², PG³and PG⁴ are as previously defined, can be obtained by reacting acompound with formula (IX) in which R¹ and R² are as previously definedwith an appropriate alcohol or diol, such as e.g. ethane-1,2-diol in thepresence of an acid, such as e.g. 4-methylbenzenesulfonic acid, in anappropriate solvent, such as e.g. toluene. The compounds of the formula(IX), wherein R¹ and R² are as previously defined, are known in the artor may be prepared in a conventional manner known by the skilledchemist.

Step 2: A compound in accordance with formula (VII), wherein R¹, R², PG³and PG⁴ are as previously defined, can be obtained by treating acompound with formula (X) in which R¹, R², PG³ and PG⁴ are as previouslydefined, with a strong base, such as e.g. buthyllithium in an inertsolvent, such as e.g. THF, and then treating the resultant mixture withDMF. The reaction is preferably carried out at a low temperature such ase.g. at −78° C.

The compounds of the formula (VIII) may be prepared as shown in Scheme 2below and by methods analogous to those described in the examples.

Step 1: A compound in accordance with formula (XII) can be obtained byreacting a compound with formula (XI), wherein R¹ is as previouslydefined, with one of the enantiomers of 2-methylpropane-2-sulfinamide inthe presence of a base, such as e.g. cesium carbonate in an organicsolvent, such as e.g. dichloromethane. The compounds of the formula(XI), are known or may be prepared in a conventional manner known by theskilled chemist.

Step 2: A compound in accordance with formula (XIII), wherein R¹ and R²are as previously defined, can be obtained by reacting a compound withformula (XII) with a Grignard reagent, such as e.g. R²MgBr, wherein R²is as previously defined, in an inert solvent, such as e.g.dichloromethane, and optionally separating the obtained intermediateinto its diastereomers by conventional methods, such as e.g. by silicagel chromatography.

Step 3: A compound in accordance with formula (XIV), wherein R¹ and R²are as previously defined, can be obtained by treating a compound withformula (XIII) with a deprotection reagent, such as e.g. hydrogenchloride in an organic solvent, such as e.g. MeOH. Typically, the acidis added while cooling and then the resultant solution is stirred untilreaction is complete e.g. at room temperature for 1-3 h.

Step 4: A compound in accordance with formula (XV), wherein R¹, R², PG¹and PG² are as previously defined, can be obtained by treating acompound with formula (XIV) with appropriate reagents for sequentiallyintroducing the suitable protecting groups PG¹ and PG². Typically, theamine compound is successively treated with two portions ofdi-tert-butyl dicarbonate in the presence ofN,N-dimethylpyridin-4-amine. The reaction is typically performed in anorganic solvent, such as e.g. dichloromethane or2-methyltetrahydrofurane, at a temperature of from about roomtemperature to about 80° C.

Step 5: A compound in accordance with formula (VIII), wherein R¹, R²,PG¹ and PG² are as previously defined, can be obtained by treating acompound with formula (XV) with synthesis gas in the presence of acatalyst, which may such as e.g. be a mixture of diacetoxypalladium,di((3S,5S,7S)-adamantan-1-yl)(butyl)-phosphine andtetramethylethylenediamine, in an organic solvent, such as for instancetoluene. Typically, the reaction is performed at about 5 bar and atabout 100° C. for about 21 h. Alternatively, a compound with formula(XV) is treated with carbon monoxide in the presence of dichlorobis(p-dimethylamino phenylditbutylphosphine) palladium (II), triethylsilaneand a base, such as for instance N,N-diisopropylethylamine. Thatreaction is typically performed in DMSO as a solvent and it is usuallycarried out at an elevated temperature and at an increased pressure fora prolonged time, such as e.g. at a temperature of, or above, 90° C., ata pressure of about 4-5 bar and for 24 h.

The protection and deprotection of functional groups is described inProtective Groups in Organic Synthesis, 4^(th) Ed, T. W. Greene and P.G. M. Wuts, Wiley-Interscience (2006) and Protecting Groups, 3^(rd) Ed,P. J. Kocienski, Georg Thieme Verlag (2005).

A further embodiment encompasses pharmaceutically acceptable salts ofthe compounds of formula (I).

A salt of a compound of formula (I) may be advantageous due to one ormore of its chemical or physical properties, such as stability indiffering temperatures and humidities, or a desirable solubility in H₂O,oil, or other solvent. In some instances, a salt may be used to aid inthe isolation or purification of the compound. In some embodiments(particularly where the salt is intended for administration to ananimal, e.g. a human, or is a reagent for use in making a compound orsalt intended for administration to an animal), the salt ispharmaceutically acceptable.

The term “pharmaceutically acceptable” is used to characterize a moiety(e.g. a salt, dosage form, or excipient) as being appropriate for use inaccordance with sound medical judgment. In general, a pharmaceuticallyacceptable moiety has one or more benefits that outweigh any deleteriouseffect that the moiety may have. Deleterious effects may include, forexample, excessive toxicity, irritation, allergic response, and otherproblems and complications.

Where the compound is sufficiently basic, pharmaceutically acceptablesalts include, but are not limited to, inorganic or organic acidaddition salts.

For reviews on suitable salts, see Berge et al., J. Pharm. Sci., 1977,66, 1-19 or Handbook of Pharmaceutical Salts: Properties, selection anduse, P. H. Stahl, P. G. Vermuth, IUPAC, Wiley-VCH, 2002.

Where an acid co-former is a solid at r.t. and there is no or onlypartial proton transfer between the compound of formula (I) and such anacid co-former, a co-crystal of the co-former and compound of formula(I) may result rather than a salt. All such co-crystal forms of thecompound of formula (I) are encompassed herein.

It is also to be understood that certain compounds of formula (I) mayexist in solvated form, e.g. hydrates, including solvates of apharmaceutically acceptable salt of a compound of formula (I).

In a further embodiment, certain compounds of formula (I) may exist asracemates and racemic mixtures, single enantiomers, individualdiastereomers and diastereomeric mixtures. Certain compounds of formula(I) may also contain linkages (e.g. carbon-carbon bonds, carbon-nitrogenbonds such as amide bonds) wherein bond rotation is restricted aboutthat particular linkage, e.g. restriction resulting from the presence ofa ring bond or double bond.

Stereoisomers may be separated using conventional techniques, e.g.chromatography or fractional crystallization, or the stereoisomers maybe made by stereoselective synthesis.

In a further embodiment, the compounds of formula (I) encompass anyisotopically-labelled (or “radio-labelled”) derivatives of a compound offormula (I). Such a derivative is a derivative of a compound of formula(I) wherein one or more atoms are replaced by an atom having an atomicmass or mass number different from the atomic mass or mass numbertypically found in nature. Examples of isotopes that may be incorporatedinclude ²H (also written as “D” for deuterium).

In a further embodiment, the compounds of formula (I) may beadministered in the form of a prodrug which is broken down in the humanor animal body to give a compound of the formula (I).

Various forms of prodrugs are known in the art. For examples of prodrugderivatives, see: Nature Reviews Drug Discovery 2008, 7, 255 andreferences cited therein.

Intermediate compounds may also exist in enantiomeric forms and may beused as purified enantiomers, diastereomers, racemates or mixtures.

Pharmacological Activity

Methods for the determination of MPO inhibitory activity are disclosedin WO 02/090575. The pharmacological activity of compounds disclosedherein was tested in the following screen (Test A) in which thecompounds were tested in the presence of ascorbate, which reacts withMPO-derived hypochlorous acid (HOCl) to form dehydro-ascorbate. The lossof ascorbate is followed by measuring absorbance at 260 nm.

Assay buffer: 100 μM diethyl triamine pentaacetic acid (DTPA) in bufferconsisting of 10 mM Na₂HPO₄/NaH₂PO₄, 3 mM KCl in 140 mM NaCl, pH 7.4.

Enzyme solution: MPO purified from the human cell line HL60, 1.38 nM(final concentration 0.7 nM) and L-ascorbate, 100 μM (finalconcentration 50 μM) in Assay buffer

Substrate solution: H₂O₂, 98 μM (final concentration 49 μM)

Forty μL of the enzyme solution was added to 0.6 μL compound seriallydiluted in DMSO. Absorbance was measured at 260 nm to obtain a compoundblank value. After an additional 10 min, 40 μL of the substrate solutionwas added and the absorbance at 260 nm was recorded between 4 and 40 minto obtain kinetic readings of enzyme activity. IC50 values of thecompounds tested were obtained using recordings of absorbance at 260 nm20 minutes after substrate addition and calculated using standardprocedures.

To detect thyroid peroxidase (TPO) inhibitory activity, the productionof hypoiodous acid (HOI) was quantified. HOI was detected by reacting itwith methionine, which is converted to dehydro-methionine, which in turnis detected by reacting it with excess iodide at acidic pH. The reactionconverts I⁻ to I₃ ⁻ that has absorbance at 353 nm. In brief, 0.6 μLcompound serially diluted in DMSO was added to 25 μL 50 nMbaculovirus-expressed recombinant human TPO (obtained from RSR Ltd,Cardiff, UK) in assay buffer (100 mM Na₂HPO₄/NaH₂PO₄, pH 7.4), afterwhich absorbance at 353 nm was read to obtain a blank value. The enzymereaction was initiated by the addition of 25 μL of a mix consisting of 2mM methionine, 20 μM NaI and 100 μM H₂O₂ in assay buffer, and stopped bythe addition of 10 μL catalase, 0.25 mg/mL. After an additional 5 min,25 μL 600 mM sulphuric acid followed by 25 μL 100 mM KI were added, andabsorbance at 353 nm was read 5 min after this addition. IC50 values ofthe compounds tested were obtained using standard procedures.

In general, the compounds disclosed herein, which were tested, had asurprisingly high selectivity for the MPO enzyme over the TPO enzymewithin the range of 220-1600 for the ratio IC₅₀ (TPO)/IC₅₀ (MPO). Themajority of the compounds (80%) demonstrated a corresponding ratio ofthe IC₅₀ values of said enzymes that was higher than 500. On the otherhand, prior art compounds according to WO 2006/062465, which weretested, demonstrated a corresponding ratio within the range of 1-92 andthe majority of those compounds (92%) had a ratio that was less than 50.Accordingly, the compounds disclosed herein approximately showed a tentimes higher MPO/TPO selectivity as compared to the selectivity of theprior art compounds according to WO 2006/062465.

The IC₅₀ values (MPO and TPO) for the Example compounds are set forth inTable 2 herein below. Also, the ratio TPO to MPO, which demonstrates theselectivity for MPO over TPO, for each Example compound, is given inTable 2.

TABLE 2 Inhibition Inhibition of MPO of TPO IC₅₀ (TPO)/ Ex. No. IC₅₀(μM) IC₅₀ (μM) IC₅₀ (MPO)  1 0.0086 4.4 512  2 0.007 8.8 1257  3 0.0074.3 614  4b 0.042 68 1620  5 0.019 8.9 468  6 0.022 10 455  7 0.015 11710  8 0.013 13 952  9 0.029 16 552 10 0.01 11 1100 11 0.014 19 1357 120.054 46 852 13 0.024 38 1609 14 0.04 28 697 15 0.049 11 224

EXAMPLES

The following examples are non-limiting examples.

The following abbreviations are employed herein:

APCI atmospheric pressure chemical ionizationaq aqueousCs₂CO₃ cesium carbonateCH₂Cl₂ dichloromethane

DIPEA N,N-diisopropylethylamine

DMAP N,N-dimethylpyridin-4-amine

DMF N,N-dimethylformamide

DMSO dimethyl sulfoxideEt₂O diethyl etherEtOAc ethyl acetateEtOH ethanolFA formic acidh hour(s)HOAc acetic acidHPLC high performance liquid chromatographyHCl hydrogen chlorideKHSO₄ potassium hydrogensulfateK₂CO₃ potassium carbonateMeCN acetonitrileMeOH methanolMgSO₄ magnesium sulfatemin minutesMS mass spectrumNa₂SO₄ sodium sulfateNaHCO₃ sodium bicarbonate

NMP N-methylpyrrolidone

NH₃ ammoniaNH₄OAc ammonium acetateNMR nuclear magnetic resonancer.t. room temperaturesat. saturatedTEA triethylamineTFA trifluoroacetic acidTHF tetrahydrofuranTMEDA tetramethylethylenediamine

The following general experimental procedures were used:

-   -   (i) Phase Separators used in the experimental are ISOLUTE® Phase        Separator columns.    -   (ii) Straight Phase flash chromatography was performed using        SP1™ Purification system from Biotage™ using normal phase silica        FLASH+™ (40M, 25M or 12M) or SNAP™ KP-Sil Cartridges (340, 100,        50 or 10).    -   (iii) Purification by preparative reverse-phase HPLC was        performed using a Kromasil® prep C8 10 μM 250×50 mm column        typically using a gradient of MeCN in water/MeCN/HOAc 95/5/0.2        as mobile phase, or a SunFire™ Prep C18 5 μM OBD 19×150 mm        column using a gradient of MeCN in water/MeCN/FA 95/5/0.2 as        mobile phase, or using a gradient of MeCN in water/MeCN/0.1 M        NH₄OAc as mobile phase.    -   (iv) ¹H NMR measurements were performed on Varian INOVA 400, 500        and 600 spectrometers or Bruker Avance 400, 500 and 600        spectrometers operating at ¹H frequencies of 400, 500 and 600        MHz, respectively. The experiments were typically recorded at        25° C.    -   (v) In general, all solvents used were analytical grade and        commercially available anhydrous solvents were routinely used        for reactions.

The X-ray diffraction analysis was performed according to standardmethods, which can be found in e.g. Kitaigorodsky, A. I. (1973),Molecular Crystals and Molecules, Academic Press, New York; Bunn, C. W.(1948), Chemical Crystallography, Clarendon Press, London; or Klug, H.P. & Alexander, L. E. (1974), X-ray Diffraction Procedures, John Wiley &Sons, New York.

X-ray powder diffraction data was measured with Corundum as an internalreference. The X-ray powder diffraction (referred to herein as XRPD)pattern was determined by mounting a sample on a zero background holder,single silicon crystal, and spreading out the sample into a thin layer.

The powder X-ray diffraction was recorded with a Theta-Theta PANalyticalX'Pert PRO (wavelength of X-rays 1.5418 Å nickel-filtered Cu radiation,Voltage 45 kV, filament emission 40 mA). Automatic variable divergenceand anitscatter slits were used and the samples were rotated duringmeasurement. Samples were scanned from 2-50° 2-theta using a 0.013° stepwidth and a 44.37 s count time, together with a PIXCEL detector (activelength 3.35° 2-theta).

The X-ray powder diffraction (XRPD) pattern was obtained inBragg-Brentano geometry. It is known that an X-ray powder diffractionpattern may be obtained which has one or more measurement errorsdepending on measurement conditions, such as equipment or machine used(Jenkins, R & Snyder, R. L. ‘Introduction to X-Ray PowderDiffractometry’ John Wiley & Sons 1996; Bunn, C. W. (1948), ChemicalCrystallography, Clarendon Press, London; Klug, H. P. & Alexander, L. E.(1974), X-Ray Diffraction Procedures). Persons skilled in the art ofX-ray powder diffraction will realize that the relative intensity ofpeaks can be affected by, for example, grains above 30 microns in sizeand non-unitary aspect ratios that may affect analysis of samples.Furthermore, it should be understood that intensities might fluctuatedepending on experimental conditions and sample preparation (e.g.preferred orientation). The following definitions have been used for therelative intensity (%): 25-100%, vs (very strong); 10-25%, s (strong);3-10%, m (medium); 1-3%, w (weak).

The skilled person will also realize that the position of reflectionscan be affected by the precise height at which the sample sits in thediffractometer and the zero calibration of the diffractometer. Thesurface planarity of the sample may also have a small effect. Hence thediffraction pattern data presented are not to be taken as absolutevalues. Generally, a measurement error of a diffraction angle in anX-ray powder diffractogram may be approximately plus or minus 0.2°2-theta, and such a degree of a measurement error should be taken intoaccount when considering the X-ray powder diffraction data.

Chemical IUPAC names are generated by software ACD/Labs 2012 provided byAdvanced Chemistry Development, Inc. Toronto, Ontario, Canada M5C 1B5.

Example 11-{2-[(1R)-1-Aminopropyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(a) tert-Butyl [(1R)-1-(2-bromo-5-chlorphenyl)propyl]carbamate

To a solution of (R)-1-(2-bromo-5-chlorophenyl)propan-1-aminehydrochloride (obtained in a similar way as the intermediate(R)-1-(2-bromo-5-chlorophenyl)ethanamine was obtained in Example 3(c)but using ethylmagnesium bromide rather than methylmagnesium bromide)(0.97 g, 3.40 mmol) in CH₂Cl₂ (15 mL) was added TEA (1.42 mL, 10.21mmol) and di-tert-butyl dicarbonate (0.82 g, 3.74 mmol). The mixture wasstirred at r.t. overnight and then washed with an aq solution of KHSO₄.The aq phase was extracted with CH₂Cl₂ (20 mL) and the combined organicsolutions were concentrated in vacuo. The residue was purified on asilica gel column using a mixture of heptane and EtOAc (gradient, 0 to15% EtOAc) as eluent, obtaining 1.42 g (quantitative yield) of the titlecompound as a white solid. MS (APCI+) m/z 349 [M+H]⁺.

(b) Di-tert-butyl [(1R)-(2-bromo-5-chlorophenyl)propyl]imidodicarbonate

To a solution of tert-butyl[(1R)-1-(2-bromo-5-chlorophenyl)propyl]carbamate (1.19 g, 3.40 mmol) in2-methyltetrahydrofuran (32 mL) were added di-tert-butyl dicarbonate(1.49 g, 6.81 mmol) and DMAP (0.83 g, 6.81 mmol). The mixture wasstirred at 50° C. and then di-tert-butyl dicarbonate (0.75 g, 3.40 mmol)and another portion of DMAP (0.42 g, 3.40 mmol) were added. Afteranother 4 h of stirring at 50° C., still another portion ofdi-tert-butyl dicarbonate (0.37 g, 1.70 mmol) was added and the mixturewas stirred at 50° C. overnight. More of di-tert-butyl dicarbonate (0.75g, 3.40 mmol) and DMAP (0.42 g, 3.40 mmol) were added and stirring wascontinued for 30 min. The mixture was washed with an aq solution ofKHSO₄ (1 M), dried trough a phase separator and then evaporated. Thecrude product was purified on a silica gel column using a mixturecomprising heptane and EtOAc as eluent (gradient, 0 to 12% EtOAc). Therewas obtained 1.10 g (72%) of the title compound as colourless oil. ¹HNMR (400 MHz, DMSO-d₆): δ 0.93 (t, 3H), 1.37 (d, 18H), 1.8-2.19 (m, 2H),5.17 (dd, 1H), 7.33 (dd, 1H), 7.57 (d, 1H), 7.65 (d, 1H).

(c)Di-tert-butyl[(1R)-1-(5-chloro-2-formylphenyl)propyl]imidodicarbonate

A mixture of di-tert-butyl[(1R)-1-(2-bromo-5-chlorophenyl)propyl]-imidodicarbonate (1.05 g, 2.34mmol), diacetoxypalladium (0.053 g, 0.23 mmol),di((3S,5S,7S)-adamantan-1-yl)(butyl)phosphine (0.26 g, 0.70 mmol) andTMEDA (0.26 mL, 1.75 mmol) was dissolved in toluene (4 mL) and theresultant solution was sealed in an autoclave. The autoclave was filledwith synthesis gas (carbon monoxide/hydrogen, 1:1) at 5 bar and thenheated in an oil-bath for 21 h at 100° C. The crude product was purifiedby silica gel chromatography using a gradient of heptane and EtOAc aseluent (0 to 18% EtOAc) to yield 0.53 g (57%) of the title compound. ¹HNMR (400 MHz, DMSO-d₆): δ 0.95 (t, 3H), 1.35 (s, 18H), 1.85-2.02 (m,1H), 2.03-2.19 (m, 1H), 5.90 (dd, 1H), 7.60 (dd, 1H), 7.69 (d, 1H), 7.87(d, 1H), 10.22 (s, 1H).

(d) Ethyl3-[(2-{(1R)-1-[bis(tert-butoxycarbonyl)amino]propyl}-4-chlorobenzyl)amino]-1H-pyrrole-2-carboxylate

To a mixture of ethyl 3-amino-1H-pyrrole-2-carboxylate hydrochloride(0.29 g, 1.53 mmol) and EtOH (99.5%, 4 mL) were added DIPEA (0.46 mL,2.66 mmol) and di-tert-butyl[(1R)-1-(5-chloro-2-formylphenyl)propyl]-imidodicarbonate (0.53 g, 1.33mmol) dissolved in EtOH (99.5%, 2.5 mL). The mixture was stirred at r.t.overnight. HOAc (0.23 mL, 4.00 mmol) was added and the mixture wasstirred at r.t. for 2.5 h whereupon sodium cyanotrihydroborate (0.088 g,1.40 mmol) was added portion-wise during a period of 3 min. The reactionmixture was then stirred at r.t. for 45 min and then diluted with water.After extracting twice with EtOAc, the organic solutions were combinedand then washed twice with an aq solution of citric acid (0.5 M), twicewith an aq solution of bicarbonate and finally with brine (halfsaturated). The solution was dried over MgSO₄ and the solvent wasremoved by evaporation to give 0.68 g (95%) of the title compound. ¹HNMR (400 MHz, DMSO-d₆): δ 0.91 (t, 3H), 1.27 (t, 3H), 1.32 (s, 18H),1.98-2.05 (m, 1H), 2.09-2.23 (m, 1H), 4.16-4.28 (m, 3H), 4.41 (dd, 1H),5.26-5.33 (m, 1H), 5.43 (s, 1H), 5.82 (bs, 1H), 6.68 (t, 1H), 7.32 (s,2H), 7.42 (s, 1H), 10.77 (s, 1H).

(e) Di-tert-butyl[(1R)-1-{5-chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-yl)methyl]phenyl}propyl]imidodicarbonate

Benzoyl isothiocyanate (0.20 mL, 1.51 mmol) was added dropwise to asolution of ethyl3-[(2-{(1R)-1-[bis(tert-butoxycarbonyl)amino]propyl}-4-chlorobenzyl)amino]-1H-pyrrole-2-carboxylate(0.68 g, 1.26 mmol) in MeOH (4 mL) was added. The mixture was stirred atr.t. for 3 h and then Cs₂CO₃ (0.86 g, 2.64 mmol) was added. The mixturewas heated at 65° C. for 2 h and then cooled to 10° C. HOAc (0.32 mL,5.67 mmol) was slowly added followed by a slow addition of water (8 mL).The mixture was extracted with EtOAc and the organic solution was dried(Na₂SO₄). The solvent was removed by evaporation and there was obtained0.94 g (quantitative yield) of the title compound.

To the crude mixture of di-tert-butyl[(1R)-1-{5-chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]phenyl}propyl]imidodicarbonate(0.69 g, 1.26 mmol) was added HCl (1.25 M in MeOH, 7.05 mL, 8.81 mmol).The mixture was stirred at 50° C. for 1 h and then cooled to 10° C.Water (2 mL) and then an aq solution of NH₃ (25%, 0.63 mL, 8.81 mmol)was slowly added to adjust the pH to 9.2. The formed precipitate wascollected by filtration and washed with a mixture of water and MeOH(2:1, 2 mL). There was obtained 0.15 g (34.6%) of the title compoundwith an enantiomeric excess of 98.8%. ¹H NMR (400 MHz, DMSO-d₆): δ 0.91(t, 3H), 1.52-1.72 (m, 2H), 4.08 (t, 1H), 5.73 (dd, 2H), 6.03 (d, 1H),6.59 (d, 1H), 7.11 (dd, 1H), 7.30 (d, 1H), 7.58 (d, 1H). [α]_(D)²⁰=+37.2° (c=0.5, EtOH). MS (APCI+) m/z 349 [M+H]⁺.

Example 21-[2-(1-Aminoethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(a) 2-(2-Bromo-5-chlorophenyl)-2-methyl-1-dioxolane

1-(2-Bromo-5-chlorophenyl)ethanone (8.29 g, 35.50 mmol) was dissolved intoluene (180 mL) in a round-bottomed flask fitted with a Dean-Starktrap. Ethane-1,2-diol (5.96 mL, 106.51 mmol) and 4-methylbenzenesulfonicacid (0.67 g, 3.91 mmol) were added and the reaction mixture was heatedat reflux for 3.5 h. The reaction mixture was cooled to r.t., an aqsolution of K₂CO₃ (1 M) was added and the layers were separated. The aqphase was extracted with toluene and the combined organic layers werewashed with water and with brine. The solution was dried (MgSO₄),filtered and the solvent was removed under reduced pressure to give 9.29g (94%) of the title compound. ¹H NMR (500 MHz, CDCl₃): δ 1.80 (s, 3H),3.78 (m, 2H), 4.08 (m, 2H), 7.13 (m, 1H), 7.52 (m, 1H), 7.66 (m, 1H).

(b) 4-Chloro-2-(2-methyl-1,3-dioxolan-2-yl)benzaldehyde

Under a nitrogen atmosphere and at −78° C., butyllithium (2.5 M inhexane, 14.73 mL, 36.82 mmol) was added dropwise to a solution of2-(2-bromo-5-chlorophenyl)-2-methyl-1,3-dioxolane (9.29 g, 33.47 mmol)in THF (100 mL) during 30 min and the resulting solution was stirred at−78° C. for 30 min. DMF (3.87 mL, 50.21 mmol) was added dropwise at −78°C. After the addition was complete, the reaction was allowed to warm tor.t. and stirring was continued for 10 min. The reaction mixture wasquenched with an aq solution of NH₄Cl (sat.) and the phases wereseparated. The aq phase was extracted twice with EtOAc. The combinedorganic layers were washed with brine, dried (MgSO₄) and the solventswere removed under reduced pressure. The product was purified by flashchromatography (silica gel, elution with a gradient of EtOAc and heptane10% to 20%) to give 5.95 (78%) of the title compound as transparentcolourless oil. ¹H NMR (500 MHz, CDCl₃): δ 1.68 (s, 3H), 3.64-3.66 (m,2H), 3.94-3.97 (m, 2H), 7.24-7.28 (m, 1H), 7.52-7.54 (m, 1H), 7.74-7.77(m, 1H), 10.52-10.53 (m, 1H).

(c) Ethyl3-{[4-chloro-2-(2-methyl-1,3-dioxolan-2-yl)benzyl]amino}-1H-pyrrole-2-carboxylate

Ethyl 3-amino-1H-pyrrole-2-carboxylate hydrochloride (3.65 g, 19.17mmol) was dissolved in EtOH (99.5%, 100 mL) and to the solution wereadded DIPEA (3.34 mL, 19.17 mmol) followed by HOAc (1.99 mL, 34.85mmol). The reaction mixture was cooled to 10° C. and then4-chloro-2-(2-methyl-1,3-dioxolan-2-yl)benzaldehyde (3.95 g, 17.43 mmol)dissolved in EtOH (99.5%, 10 mL) was added. The reaction mixture wasallowed to reach r.t. for 1 h. Sodium cyanotrihydroborate (1.31 g, 20.91mmol) was added and the mixture was stirred at r.t. for 18 h. Thereaction mixture was quenched with water (50 mL) and the pH was adjustedto ˜11 with NaOH. The mixture was extracted trice with EtOAc. Thecombined organic layers were washed with brine, dried (MgSO₄) and thesolvent was removed under reduced pressure. The product was purified byflash chromatography (isocratic, heptane/EtOAc, 90/10) to give 4.61 g(72%) of the title compound as a colourless gum. ¹H NMR (400 MHz,CDCl₃): δ 1.3-1.37 (m, 3H), 1.71 (s, 3H), 3.79-3.85 (m, 2H), 4.05-4.1(m, 2H), 4.25-4.35 (m, 2H), 4.51-4.57 (m, 2H), 5.64-5.71 (m, 1H),6.66-6.73 (m, 1H), 7.2-7.24 (m, 1H), 7.4-7.45 (m, 1H), 7.57-7.6 (m, 1H).

(d)1-[4-Chloro-2-(2-methyl-1,3-dioxolan-2-yl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

Benzoyl isothiocyanate (1.70 mL, 12.64 mmol) was added dropwise to asolution of ethyl3-{[4-chloro-2-(2-methyl-1,3-dioxolan-2-yl)benzyl]amino}-1H-pyrrole-2-carboxylate(4.61 g, 12.64 mmol) in MeOH (14 mL) and the reaction mixture wasstirred at r.t. for 10 min. A further portion of benzoyl isothiocyanate(0.17 mL, 1.26 mmol) was added and the reaction was stirred for 30 min.Cs₂CO₃ (8.85 g, 27.17 mmol) was added and the mixture was stirred at 60°C. for 1.5 h. The solvent was removed under reduced pressure. Water (30mL) and EtOAc (70 mL) were added and a precipitate being formed in theorganic phase was isolated by filtration. After washing the solid withEt₂O, there was obtained 4.71 g (99%) of the title compound as a whitesolid. ¹H NMR (600 MHz, DMSO-d₆): δ 1.75 (s, 3H), 3.78-3.83 (m, 2H),4.05-4.11 (m, 2H), 5.63-5.67 (m, 1H), 6.56-6.63 (m, 1H), 6.93-6.98 (m,1H), 7.17-7.22 (m, 1H), 7.45-7.5 (m, 1H). MS (APCI−) m/z 376 [M−H]⁻.

(e)1-(2-Acetyl-4-chlorobenzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

To a suspension of1-[4-chloro-2-(2-methyl-1,3-dioxolan-2-yl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one(4.71 g, 12.47 mmol) in CH₂Cl₂ (25 mL) was added TFA (9.26 mL, 124.65mmol). The reaction mixture was stirred at r.t. for 2 h and then an aqsolution of NaOH (3.8 M) was added until a pH of approximately 11 wasreached. The formed solid was isolated by filtration and the product waswashed with CH₂Cl₂ and then with Et₂O. There was obtained 3.49 g (84%)of the title compound as a white solid. ¹H NMR (600 MHz, DMSO-d₆): δ2.69 (s, 3H), 5.63-5.7 (m, 1H), 5.79-5.83 (m, 2H), 6.79-6.86 (m, 1H),6.89-6.95 (m, 1H), 7.4-7.5 (m, 1H), 7.96-8.04 (m, 1H). MS (APCI−) m/z332 [M−H]⁻.

(f)1-[2-(1-Aminoethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

To a mixture of1-(2-acetyl-4-chlorobenzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one(3.39 g, 10.16 mmol), HOAc (20 mL) and NMP (40 mL) was addedhydroxylamine hydrochloride (0.78 g, 11.18 mmol) and the mixture wasthen stirred at 60° C. for 18 h. Zinc (1.02 g, 15.59 mmol) was added andthe reaction mixture was stirred at 60° C. for 4 h. A further portion ofzinc (1 g, 15.30 mmol) was added and the mixture was then stirred at 60°C. for additional 4 h. Another portion of zinc (1 g, 15.30 mmol) wasadded and after additional 20 h stirring at 80° C. still another portionof zinc (3 g, 45.89 mmol) was added. The mixture was then stirred at 80°C. for 40 h and the remaining solids were filtered off. The product waspurified by preparative HPLC (3 injections) on a C8 column using agradient of 0-70% MeCN in a mixture of water/MeCN/HOAc (95/5/0.2) over15 min (the elution started with 0% MeCN for 5 min). There was obtained0.86 g (25%) of the title compound. ¹H NMR (600 MHz, DMSO-d₆, 40° C.): δ1.33-1.37 (m, 3H), 4.38-4.45 (m, 1H), 5.64-5.85 (m, 2H), 6.01-6.05 (m,1H), 6.59-6.64 (m, 1H), 7.1-7.15 (m, 1H), 7.27-7.31 (m, 1H), 7.64-7.66(m, 1H). MS (APCI−) m/z 333 [M−H]⁻.

Example 31-{2-[(1R)-1-Aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(a) S-(E orZ)—N-(2-Bromo-5-chlorobenzylidene)-2-methylpropane-2-sulfinamide

2-Bromo-5-chlorobenzaldehyde (4 g, 18.23 mmol) was dissolved in CH₂Cl₂(130 mL) and to the solution was added (S)-2-methylpropane-2-sulfinamide(2.32 g, 19.14 mmol) followed by cesium carbonate (5.94 g, 18.23 mmol).The mixture was refluxed over night and then diluted with brine andCH₂Cl₂. The organic layer was dried through a phase-separator and thenevaporated. The product was purified by silica gel chromatography usinga mixture comprising EtOAc and heptane as eluent (gradient, 0%-25%EtOAc) to give 5.60 g (95%) of the title compound as a solid. ¹H NMR(400 MHz, DMSO-d₆) δ 1.21 (s, 9H), 7.61 (dd, 1H), 7.84 (d, 1H), 7.98 (d,1H), 8.75 (s, 1H).

(b)(S)—N-[(1R)-1-(2-Bromo-5-chlorophenyl)ethyl]-2-methylpropane-2-sulfinamide

S-(E or Z)—N-(2-Bromo-5-chlorobenzylidene)-2-methylpropane-2-sulfinamide(5.41 g, 16.78 mmol) was dissolved in CH₂Cl₂ (200 mL) under a nitrogenatmosphere and to the resultant solution was added methylmagnesiumbromide (11.18 mL, 33.55 mmol) at −45° C. The mixture was stirredbetween −40° C. and −50° C. for 4 h and was then slowly allowed to reachr.t. over night. A solution of NH₄Cl (sat., 50 mL) was added followed bywater (100 mL). The layers were separated using a phase separator andthe aqueous layer was extracted three times with CH₂Cl₂ (150 mL). Thecombined organic layers were concentrated in vacuo. The residue waspurified by silica gel chromatography using a mixture comprising heptaneand EtOAc (gradient, 10% to 60% EtOAc). The fractions containing themajor diastereomer—which eluted last from the column—were pooled and thesolvent removed by evaporation. There was obtained 5.28 g (93%) of thetitle compound. ¹H NMR (400 MHz, DMSO-d₆): δ 1.15 (s, 9H), 1.30 (d, 3H),4.65 (m, 1H), 6.10 (d, 1H), 7.30 (d, 1H), 7.65 (d, 1H), 7.70 (s, 1H). MS(APCI+) m/z 340 [M+H]⁺.

The absolute configuration of the title compound was determined byvibrational circular dichroism (VCD) spectroscopy using a material thatwas obtained from a similar experiment as in Example 3(b). Based onresults from comparing the obtained experimental spectrum with simulatedspectra of the two possible diastereomers using density functionaltheory calculations, there was a clear agreement between theexperimental spectrum and the simulated spectrum of the diastereomerhaving R-configuration at the asymmetric carbon atom.

(c). (R)-1-(2-Bromo-5-chlorophenyl)ethanamine

(S)—N-[(1R)-1-(2-Bromo-5-chlorophenyl)ethyl]-2-methylpropane-2-sulfinamide(5.25 g, 15.50 mmol) was treated with a MeOH solution of HCl (1.25 M,150 mL, 187.50 mmol) at r.t. for 1.5 h. The solvent was removed byevaporation. The remainder was dissolved in CH₂Cl₂ (200 mL) and thesolution washed with aq NaHCO₃ (100 mL). The aq phase was extracted withCH₂Cl₂ (200 mL) and the combined organic layers were concentrated invacuo, to give 4.02 g (quantitative yield) of the title compound, whichwas used in the next step without further purification. ¹H NMR (400 MHz,CDCl₃): δ 1.40 (d, 3H), 4.40 (q, 1H), 7.10 (d, 1H), 7.40 (d, 1H), 7.60(s, 1H).

(d) tert-Butyl [(1R)-1-(2-bromo-5-chlorophenyl)ethyl]carbamate

To a solution of (R)-1-(2-bromo-5-chlorophenyl)ethanamine (3.64 g, 15.52mmol) in CH₂Cl₂ (150 mL) was added TEA (2.58 mL, 18.63 mmol) anddi-tert-butyl dicarbonate (3.73 g, 17.07 mmol). The mixture was stirredat room temperature for 3.5 h and then washed with an aq solution ofKHSO₄ (1M, 100 mL). The aq phase was extracted with CH₂Cl₂ (100 mL) andthe combined organic solutions were concentrated in vacuo to give 5.83 g(quantitative yield) of the crude title compound. ¹H NMR (400 MHz,CDCl₃): δ 1.25-1.50 (d, 3H), 1.60 (s, 9H), 4.75-5.00 (m, 1H), 7.10 (dd,1H), 7.30 (m, 1H), 7.50 (d, 1H).

(e) Di-tert-butyl [(1R)-1-(2-bromo-5-chlorophenyl)ethyl]imidodicarbonate

To a solution of tert-butyl[(1R)-1-(2-bromo-5-chlorophenyl)ethyl]carbamate (5.19 g, 15.51 mmol) in2-methyltetrahydrofuran (150 mL) was added di-tert-butyl dicarbonate(5.08 g, 23.26 mmol) and DMAP (2.84 g, 23.26 mmol). The mixture wasstirred at room temperature for 16 h whereupon more di-tert-butyldicarbonate (1.69 g, 7.75 mmol) and DMAP (0.95 g, 7.75 mmol) were added.The mixture was stirred at 50° C. for 4.5 h and was then concentrated invacuo. The remainder was dissolved in CH₂Cl₂ (150 mL) and the solutionwas washed with KHSO₄ (1M, 100 mL) using a phase separator. The aq phasewas extracted with CH₂Cl₂ (100 mL) and the combined organic solutionswere concentrated in vacuo. The crude product was purified twice bychromatography on silica gel using a mixture of heptane and EtOAc aseluent (gradient, 30% to 70% of EtOAc). There was obtained 5.05 g (75%)of the title compound. ¹H NMR (400 MHz, DMSO-d₆): δ 1.2-1.4 (m, 21H),4.70 (m, 1H), 7.25 (dd, 1H), 7.55 (d, 1H), 7.65 (d, 1H).

(f) Di-tert-butyl[(1R)-1-(5-chloro-2-formylphenyl)ethyl]imidodicarbonate

Di-tert-butyl [(1R)-1-(2-bromo-5-chlorophenyl)ethyl]imidodicarbonate(4.27 g, 9.83 mmol), diacetoxypalladium (0.22 g, 0.98 mmol),di((3S,5S,7S)-adamantan-1-yl)(butyl)phosphine (1.06 g, 2.95 mmol) andTMEDA (1.10 mL, 7.37 mmol) were dissolved in toluene (18 mL) and theresultant solution was sealed in an autoclave. The autoclave was filledwith synthesis gas (carbon monoxide/hydrogen, 1:1) at 5 bar and thenheated in an oil-bath for 21 h at 100° C. The crude product was purifiedby silica gel chromatography using a gradient of heptane and EtOAc aseluent (0 to 20% EtOAc) to yield 2.15 g (57%) of the title compound. ¹HNMR (400 MHz, DMSO-d₆): δ 1.34 (s, 18H), 1.58 (d, 3H), 6.06 (q, 1H),7.61 (dd, 1H), 7.67 (d, 1H), 7.87 (d, 1H), 10.14 (s, 1H).

(g) Ethyl3-[(2-{(1R)-1-[bis(tert-butoxycarbonyl)amino]ethyl}-4-chlorobenzyl)amino]-1H-pyrrole-2-carboxylate

To a mixture of ethyl 3-amino-1H-pyrrole-2-carboxylate hydrochloride(1.14 g, 5.99 mmol) and EtOH (99.5%, 20 mL) was addedN-ethyl-N-isopropylpropan-2-amine (1.82 mL, 10.42 mmol) followed bydi-tert-butyl [(1R)-1-(5-chloro-2-formylphenyl)ethyl]-imidodicarbonate(2.00 g, 5.21 mmol) dissolved in EtOH (99.5%, 5 mL). The mixture wasstirred at room temperature overnight. HOAc (0.90 mL, 15.63 mmol) wasadded and the mixture was stirred at room temperature for 6 h whereuponsodium cyanotrihydroborate (0.34 g, 5.47 mmol) was added portion-wiseduring a period of 3 min. The reaction mixture was then stirred at roomtemperature for 1 h and then diluted with water. After extracting with amixture of EtOAc (25 mL) and toluene (25 mL), the aq solution wasextracted with EtOAc (25 mL). The combined organic solutions were washedtwice with an aq solution of citric acid (0.5 M, 25 mL), twice with anaq solution of bicarbonate and finally with brine (half sat.). Thesolution was dried over MgSO₄ and then the solvent was removed byevaporation at 40° C. to give 2.93 g (quantitative yield) of the titlecompound. ¹H NMR (400 MHz, DMSO-d₆): δ 1.27 (t, 3H), 1.31 (s, 18H), 1.59(d, 1H), 4.21 (m, 3H), 4.37 (dd, 1H), 5.43 (m, 1H), 5.51 (q, 1H), 5.82(bs, 1H), 6.69 (t, 1H), 7.32 (s, 2H), 7.43 (s, 1H), 10.79 (s, 1H). MS(APCI+) m/z 522 [M+H]⁺.

(h) Di-tert-butyl[(1R)-1-{5-chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]phenyl}ethyl]imidodicarbonate

To a solution of ethyl3-[(2-{(1R)-1-[bis(tert-butoxycarbonyl)amino]ethyl}-4-chlorobenzyl)amino]-1H-pyrrole-2-carboxylate(2.79 g, 4.01 mmol) in MeOH (12 mL) was added benzoyl isothiocyanate(0.79 g, 4.81 mmol) dropwise. The mixture was stirred at rt overnightand then Cs₂CO₃ (2.74 g, 8.42 mmol) was added. The mixture was heated at60° C. for 3 h and then cooled to 10° C. HOAc (1.03 mL, 18.05 mmol) wasadded slowly followed by a slow addition of water (24 mL). The formedprecipitate was collected by filtration and then washed with MeOH togive 2.09 g (97%) of the title compound as beige solid. ¹H NMR (400 MHz,DMSO-d₆): δ 1.33 (s, 18H), 1.67 (d, 3H), 5.48-5.7 (m, 3H), 5.91 (d, 1H),6.67 (d, 1H), 7.25 (dd, 1H), 7.32 (d, 1H), 7.48 (d, 1H), 12.43 (s, 2H).MS (APCI+) m/z 533 [M−H]⁻.

(i)1-{2-[(1R)-1-Aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

To a crude mixture of di-tert-butyl[(1R)-1-{5-chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]phenyl}ethyl]imidodicarbonate(1.67 g, 1.74 mmol) was added HCl (1.25 M, 24.37 mL, 30.46 mmol). Themixture was stirred at 50° C. for 1 h and then cooled with an ice-bath.Water (3 mL) was added and an aq solution of NH₃ (25%) was added slowlyto pH 9.3. The formed precipitate was collected by filtration to obtain0.39 g (67%) of the title compound as a beige solid with an enantiomericexcess of 99.9%. ¹H NMR (400 MHz, DMSO-d₆): δ 1.32 (d, 3H), 4.36 (m,1H), 5.74 (dd, 1H), 6.04 (d, 1H), 6.59 (d, 1H), 7.11 (dd, 1H), 7.31 (d,1H), 7.65 (d, 1H). [α]_(D) ²⁰=+76.8° (c=0.3, MeOH). MS (APCI+) m/z 335[M+H]⁺.

(j)1-{2-[(1R)-1-Aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(Example 3j, prepared as described above) (690 g, 2.06 mol), ethanol(11040 mL) and water (2760 mL) was added to a 50 L vessel undernitrogen. The mobile and free moving slurry was heated to 70° C. for 2.5h. The reaction was cooled to rt after stirring at 70° C. for 2.5 h. Themixture was filtered (took approximately 2 h to filter) and then washedwith 20% water/ethanol (690 mL/2760 mL). The solid was then dried in theoven under vacuum at 50° C. for 3 days to give 633 g (91% yield). ¹H NMRindicated a purity of >95%. ¹H NMR assay indicated a purity of101%+/−2%, LC indicated a purity of 99.7%, Karl Fischer titrationindicated 0.86% water, Pd content indicated 3 ppm and chiral purityindicated 99.9% ep.

The solid residue was found to be crystalline by XRPD and a typicaldiffractogram is displayed in FIG. 4. Characteristic peak positions arelisted below.

XRPD pattern 2-Theta (°) 7.4 (vs), 9.0 (s), 10.8 (vs), 14.8 (vs), 20.2(vs), 22.7 (vs), 23.5 (vs), 25.0 (vs), 30.7 (vs).

The absolute configuration of the title compound was confirmed by singlecrystal X-ray analysis of the mesylate salt of Example 3.

Example 3, Alternative Preparation1-{2-[(1R)-1-Aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(a) S-(E orZ)—N-(2-Bromo-5-chlorobenzylidene)-2-methylpropane-2-sulfinamide

A suspension of cesium carbonate (148.5 g, 0.46 mol),2-bromo-5-chlorobenzaldehyde (100.0 g, 0.46 mmol) and(S)-2-methylpropane-2-sulfinamide (55.1 g, 0.46 mol) in toluene (600 mL)was stirred for 2 h at 40±5° C. then cooled to 30±5° C. The mixture wasfiltered and the cake washed with toluene (200 mL). The filtrates werecombined and concentrated under vacuum. Heptane (1 L) was added and themixture concentrated under vacuum. This was repeated until the contentof toluene was no more than 15.0%. The solution was cooled to 15±5° C.and stirred for 1 h. The mixture was filtered and the cake washed withheptane. The solid was dried under vacuum to give the title compound(141.0 g, 95.2%).

(b)(S)—N-[(1R)-1-(2-Bromo-5-chlorophenyl)ethyl]-2-methylpropane-2-sulfinamide

To a solution of S-(E orZ)—N-(2-bromo-5-chlorobenzylidene)-2-methylpropane-2-sulfinamide (100.0g, 0.31 mol) in DCM (1.5 L) at 0±5° C. was charged MeMgBr (2.8 M in2-MeTHF, 0.34 mmol) over 12 h. After an additional 14 h aqueous ammoniumchloride (20 wt %, 2 L) was added at 0±10° C. The organic layer waswashed twice with saturated NaCl solution (500 mL) and concentratedunder vacuum. Heptane (500 mL) was charged and the mixture concentratedunder vacuum. This was repeated until the content of both DCM and2-MeTHF was no more than 5.0%. Petroleum ether 60-90° C. (800 mL) wasadded and the contents heated to 70-80° C. then cooled to 31-35° C. Themixture was filtered and washed with petroleum ether 60-90° C. (100 mL).After drying under vacuum at 40° C. there was obtained 74.0 g, (70.5%)of the title compound.

(c) tert-Butyl [(1R)-1-(2-bromo-5-chlorophenyl)ethyl]carbamate

To(S)—N-[(1R)-1-(2-Bromo-5-chlorophenyl)ethyl]-2-methylpropane-2-sulfinamide(720 g, 2.1 mol) and 2-MeTHF (3.6 L) was added concentrated HCl (574.0mL, 6.8 mol) over 1 h at 25±5° C. The solution was stirred for 2 h thenaqueous NaOH (15 wt %, 1.8 L) added until a pH of 9 was reached. BOC₂a(485.3 g, 2.2 mol) was added at 20±10° C. and the mixture stirred for 4h. The mixture was separated and the organic layer washed with aqueousNaOH (4 wt %, 2.0 L) then with aqueous NaCl (20 wt %, 2.0 L), twice. Theorganic was concentrated under vacuum and heptane (3.6 L) added. Themixture was concentrated again. This process was repeated until the2-MeTHF content was no more than 5.0%. The solution was cooled to 10±5°C. The mixture was filtered and washed with heptane. After drying undervacuum at 40° C. there was obtained 645.0 g (90.7%) of the titlecompound.

(d) Di-tert-butyl [(1R)-1-(2-bromo-5-chlorophenyl)ethyl]imidodicarbonate

tert-Butyl [(1R)-1-(2-bromo-5-chlorophenyl)ethyl]carbamate (640 g 1.913mol), DMAP (350.1 g, 2.870 mol) and 2-MeTHF (3.8 L) was heated to 75-80°C. BOC₂O (542.1 g, 2.487 mol) was added dropwise. The solution wasstirred at 75-80° C. for 4 h then cooled to 25-30° C. The organic layerwas washed with aqueous NaOH (4 wt %, 2 L) then twice with aqueous NaCl(20 wt %, 2 L). The organic layer was concentrated under vacuum thenEtOH (3.2 L) added. The mixture was concentrated under vacuum. Thisprocess was repeated until the 2-MeTHF content was no more than 5.0%.The solution was heated to 40±5° C. and water (1.6 L) was added. Themixture was cooled to 10±5° C. The mixture was filtered and washed withEtOH:water 1:1 (1.9 L). After drying under vacuum there was obtained thetitle compound, 770.0 g, (92.0%).

(e) Di-ter t-butyl[(1R)-1-(5-chloro-2-formylphenyl)ethyl]imidodicarbonate

A mixture of DMSO (800 mL), N-ethyl-N-isopropyl-propan-2-amine (48.1 mL,276.0 mmol) and triethylsilane (103 mL, 644.0 mmol) was agitated andplaced under vacuum (100 mbar) and re-pressurised with nitrogen, threetimes. The mixture was transferred to a vessel containing di-tert-butyl[(1R)-1-(2-bromo-5-chlorophenyl)ethyl]imidodicarbonate (80.00 g, 184.0mmol).Bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II)6.514 g, 9.20 mmol) was added. The contents were pressurised withnitrogen to 2 bar and released back to atmospheric pressure three times,then pressurised with carbon monoxide to 2 bar and released back toatmospheric pressure three times. The vessel was pressurised to 4 barwith carbon monoxide, agitation started and then heated to 90° C. for 24h. The contents was cooled to 20° C. and filtered. The lower layer wasremoved and added to a mixture of heptane (400 mL) and water (400 mL).The upper layer was retained and the lower layer was extracted withheptane (200 mL). The lower layer was removed. The two upper layers werecombined and washed with water (400 mL) then concentrated to an oilcontaining the title compound, (66.5 g, 94.0%).

(f)1-{2-[(1R)-1-Aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

To a slurry of di-tert-butyl[(1R)-1-{5-chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]phenyl}ethyl]imidodicarbonate(30.0 g, 52.1 mmol) in methanol (200 mL) at 40-45° C. was added 4.0 MHCl in methanol (79.2 mL, 316.8 mmol). The mixture was stirred at 40-45°C. for 1 h then cooled to 20-25° C. Water (96.5 mL) was added. Thesolution was cooled to 0-10° C. and ammonium hydroxide (56.6%, 31.5 mL,448 mmol) added to pH 8.5-10. The slurry was filtered and washed withmethanol (60 mL) then water (60 mL) then methanol (60 mL). After dryingat 70° C. under vacuum there was obtained 16.14 g (92.2%) of the titlecompound.

Example 4a1-{2-[(1S)-1-Aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

The two enantiomers of1-[2-(1-aminoethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one(Example 2) were obtained by chiral chromatography by using a Chiralpak®IA column (250×4.6 mm, 5 μm) using a mobile phase comprising heptane,EtOH and TEA (80/20/0.1). Starting with 0.66 g of the racemic compoundaccording to Example 2, 0.28 g of the title compound with anenantiomeric excess of 84% was obtained. [α]_(D) ²⁰=−14.9° (c=0.5,MeOH).

Example 4b1-{2-[(1S)-1-Aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

Starting with 2.0 g of 2-bromo-5-chlorobenzaldehyde and using a similarprotocol as described in Example 3 but employing the R-enantiomer of2-methylpropane-2-sulfinamide rather than the S-enantiomer afforded 0.40g of the title compound with an enantiomeric excess of 99.2%. ¹H NMR(400 MHz, DMSO-d₆) δ 1.34 (d, 3H), 1.91 (s, 3H), 4.41 (q, 1H), 5.57-5.87(m, 2H), 6.04 (d, 1H), 6.60 (d, 1H), 7.13 (dd, 1H), 7.31 (d, 1H), 7.66(d, 1H). [α]_(D) ²⁰=−43.9° (c=0.5, MeOH).

Example 51-{4-Chloro-2-[1-(methylamino)ethyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

1-(2-Acetyl-4-chlorobenzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one(0.29 g, 0.88 mmol) was suspended in EtOH (99.5%, 2.0 mL) and to themixture were added tetraisopropoxytitanium (0.52 mL, 1.79 mmol) andmethanamine (2 M in THF, 2.68 mL, 5.36 mmol). The mixture was stirred atr.t. for 4 h and then sodium tetrahydroborate (66.9 mg, 1.77 mmol) wasadded. After stirring at r.t. for 30 min, water and NH₃ (2 M in MeOH)were added to adjust the pH to 11. The suspension was stirred at r.t.for 30 min and then the precipitate was filtered off and washed withMeOH and EtOAc. The filtrate was removed under reduced pressure and theproduct was then purified by preparative HPLC on a C18 column using agradient (0-30% MeCN in water, MeCN and FA, 95/5/0.2) as mobile phase.There was obtained 0.13 g (43%) of the title compound. ¹H NMR (500 MHz,DMSO-d₆): δ1.35 (d, 3H), 2.29 (s, 3H), 4.14 (q, 1H), 5.73 (q, 2H), 6.00(d, 1H), 6.65 (d, 1H), 7.18 (dd, 1H), 7.32 (d, 1H), 7.60 (d, 1H), 8.17(s, 1H), 12.50 (s, 1H). MS (APCI+) m/z 349 [M+H]⁺.

Example 61-{4-Chloro-2-[(ethylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(a) 1-Bromo-4-chloro-2-(diethoxymethyl)benzene

A reactor (5 L) was charged with triethyl orthoformate (379 mL, 2278mmol) under a nitrogen atmosphere and then under stirring,2-bromo-5-chlorobenzaldehyde (250 g, 1139 mmol) was added in portionsduring 50 min. The reactor was cooled during the addition to keep thereaction temperature below 21° C. The mixture was stirred at 17° C. for3 h, another portion of triethyl orthoformate (100 mL, 601 mmol) wasadded and stirring was then continued for additional 3.5 h. Heptane (300mL) was added and the mixture was filtered through celite. The filtercake was washed with heptane (200 mL) and the combined solutions wereevaporated. The residue was co-evaporated four times with heptane (200mL) and then purified in portions by silica gel flash chromatographyusing a mixture comprising EtOAc and hexane as mobile phase (gradient,0%-50% EtOAc). There was obtained 280 g (84%) of the title compound. ¹HNMR (400 MHz, DMSO-d₆): δ 1.13 (t, 6H), 3.43-3.69 (m, 4H), 5.51 (s, 1H),7.36 (dd, 1H), 7.48 (d, 1H), 7.63 (d, 1H).

(b) 4-Chloro-2-(diethoxymethyl)benzaldehyde

A reactor (5 L) was charged with1-bromo-4-chloro-2-(diethoxymethyl)benzene (251 g, 855 mmol) and2-methyltetrahydrofuran (3 L) under a nitrogen atmosphere and themixture was cooled to −60° C. To the solution was added n-butyllithium(2.5 M in hexane, 342 mL, 855 mmol) via tubing. After stirring for 40min, DMF (73 mL, 940 mmol) was added over a period of 12 min. Thetemperature of the mixture rose to −49° C. during said addition. Themixture was stirred for 40 min and then the temperature was increased to0° C. After additional 30 min stirring, water (300 mL) was added for aperiod of 5 min followed by a half sat. solution of brine (1.5 L). Thelayers were separated and the aq phase was extracted with2-methyltetrahydrofuran (1 L). The organic solutions were washed withsat. brine, dried (MgSO₄) and evaporated overnight at 30° C. There wasobtained 193 g of the title compound as light brown oil with a purity of87% (81% effective yield). ¹H NMR (400 MHz, CDCl₃): δ 1.15 (m, 6H),3.50-3.70 (m, 4H), 5.90 (s, 1H), 7.40 (dd, 1H), 7.70 (d, 1H), 7.80 (d,1H).

(c) Ethyl3-{[4-chloro-2-(diethoxymethyl)benzyl]amino}-1H-pyrrole-2-carboxylate

A reactor (10 L) was charged with4-chloro-2-(diethoxymethyl)benzaldehyde (181 g, 649 mmol) and MeOH (1 L)and to the mixture was added DIPEA (92 g, 714 mmol) dissolved in MeOH(100 mL). Ethyl 3-amino-1H-pyrrole-2-carboxylate hydrochloride (132 g,648 mmol) was added together with MeOH (700 mL). The mixture was stirredat 20° C. overnight and then HOAc (78 g, 1298 mmol) was added. Sodiumcyanoborohydride (41 g, 649 mmol) was added in several portions under aperiod of 7 min with stirring and cooling, so that the temperature didnot rise above 27° C. The solution was stirred for 40 min and then water(1.8 L) was added. The mixture was extracted twice with CH₂Cl₂ (1 L) andthe combined organic solutions were dried (K₂CO₃) and concentrated to avolume of 1300 mL. After four days the mixture was concentrated in thepresence of MeOH to give a MeOH solution (approximately 1 L) of thetitle compound. The material was used in the next step without furtherpurification. ¹H NMR (400 MHz, MeOH-d₄): δ1.20 (t, 6H), 1.30 (t, 3H),3.25 (m, 1H), 3.40-3.60 (m, 5H), 4.20 (q, 2H), 4.40 (s, 2H), 5.60 (d,1H), 5.65 (s, 1H), 6.70 (d, 1H), 7.20 (m, 1H), 7.30 (d, 1H), 7.50 (d,1H).

(d)1-[4-Chloro-2-(diethoxymethyl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

To a MeOH solution (approximately 1 L) of ethyl3-{[4-chloro-2-(diethoxymethyl)-benzyl]amino}-1H-pyrrole-2-carboxylate(550 mmol) was slowly added benzoyl isothiocyanate (89 g, 677 mmol) sothat the reaction temperature was kept between 17° C. and 22° C. Themixture was stirred for 15 min and another portion of benzoylisothiocyanate (13.5 g, 82.5 mmol) was added and after additionalstirring for 50 min, still another portion of benzoyl isothiocyanate (8g, 50 mmol) was added. The mixture was stirred for 30 min and thenCs₂CO₃ (383 g, 1177 mmol) was added during a period of 15 min. Thetemperature was increased to 30° C. for 30 min and then to 40° C. for 20min. The mixture stirred at 50° C. for 4 h and then at 10° C. overnight.HOAc (140 mL) was added at 10° C. during a period of 20 min and then thetemperature of the mixture was increased to 19° C. To the formedprecipitate was slowly added water (1.4 L) and the solid material wasisolated by filtration. The filter cake was washed with toluene (2 L)and then dried in vacuo for 3 days. There was obtained 201 g (80%, twosteps) of the title compound. ¹H NMR (600 MHz, DMSO-d₆): δ1.20 (m, 6H),3.50-3.70 (m, 4H), 5.80 (s, 2H), 6.00 (s, 1H), 6.75 (d, 1H), 7.30 (m,1H), 7.50 (s, 1H), 11.70-12.70 (b, 2H). MS (APCI+) m/z 395 [M+H]⁺.

(e)5-Chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde

To a cooled mixture of TFA (1.89 mL, 25.39 mmol) and CH₂Cl₂ (8 mL) wasadded1-[4-chloro-2-(diethoxymethyl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one(1 g, 2.54 mmol). The ice-bath was removed and the mixture was stirredat r.t. for 2.5 h. The formed precipitate was isolated by filtration andwashed with CH₂Cl₂ to result in 0.69 g (85%) of the title compound as asolid. ¹H NMR (500 MHz, DMSO-d₆): δ 6.02 (s, 2H), 6.09 (s, 1H), 6.88 (d,1H), 7.31 (t, 1H), 7.60 (dd, 1H), 8.09 (d, 1H), 10.24 (s, 1H), 12.41 (s,1H), 12.51 (s, 1H). MS (APCI+) m/z 320 [M+H]⁺.

(f)1-{4-Chloro-2-[(ethylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

5-Chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(22 mg, 0.68 mmol) and ethanamine (2 M in THF, 3.39 mL, 6.79 mmol) weredissolved in MeOH (5 mL) in a microwave vial. The reaction mixture washeated by microwave irradiation at 100° C. for 5 min and then at 140° C.for 75 min. Sodium tetrahydroborate (205 mg, 5.43 mmol) was added andthe reaction mixture was stirred at r.t. for 3 days. The mixture wasquenched by the addition of water. The solvents were evaporated and thecrude product was purified by preparative HPLC using a gradient of 0-30%MeCN in water/MeCN/FA (95/5/0.2). ¹H NMR (600 MHz, DMSO-d₆): δ 1.10 (t,3H), 2.65 (q, 2H), 3.85 (s, 2H), 5.76 (s, 2H), 6.10 (d, 1H), 6.69 (d,1H), 7.19 (dd, 1H), 7.30 (d, 1H), 7.45 (d, 1H). MS (APCI+) m/z 349[M+H]⁺.

Example 71-[2-(Aminomethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

5-Chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(see Example 6(e)) (194 mg, 0.61 mmol) was added to a mixture ofhydroxylamine hydrochloride (46 mg, 0.67 mmol) and HOAc (80%, 4 mL). Themixture was stirred at r.t. for 5 h and then zinc (198 mg, 3.03 mmol)was added. The reaction mixture was stirred at 60° C. for 2 h. An aqsolution of NaOH (1 M) was added to adjust the pH to 12. The solventswere removed under reduced pressure and the residue was purified bypreparative HPLC on a C8 column using a gradient of 5-45% MeCN in water,MeCN and FA (95/5/0.2) buffer. ¹H NMR (500 MHz, MeOH-d₄) δ 4.40 (s, 2H),5.75 (s, 2H), 6.15 (d, 1H), 6.97 (d, 1H), 7.31 (d, 1H), 7.34 (dd, 1H),7.53 (d, 1H). MS (APCI+) m/z 321 [M+H]⁺.

Example 7, Alternative Preparation1-[2-(Aminomethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

A suspension of5-chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(see Example 6(e)) (500 g) and hydroxylamine hydrochloride (88.1 g, 1.1eq) in DMF (5000 mL) was heated at 50° C. for 3 h. The reaction wascooled to 18-25° C. overnight and the solvent was removed in vacuo(maximum water bath temperature 55° C.) and water (7500 mL) was added tothe residue. 1 M NaOH (aq) was then added to the suspension to adjustthe pH to 10 (2000 mL used). After stirring for 1 h, the solid wasfiltered, washed with water (2×1785 mL) and pulled dry. Further dryingin a vacuum oven at 45° C. yielded the intermediate oxime as a whitesolid (395.0 g). To a suspension of combined batches of this material(450.7 g) in acetic acid (6760 mL) at 18-25° C., zinc (50 g) was added.The reaction was then warmed to 50-60° C. Additional zinc (830.3 g,total added 880.3 g, 10 eq) was added portion-wise at 50-60° C. Thereaction was stirred at 50° C. for 18 h. The reaction was filtered (hot)and the filtrate concentrated in vacuo (maximum water bath temperature55° C.). The resulting solid was slurried in 20% HCl (aq, 3755 mL) for 1h at 18-25° C. then filtered, washed with 20% HCl (aq, 1500 mL) thenwater (2×1500 mL) and pulled dry. The solid was then taken up in water(9014 mL) and MeCN (3155 mL). The pH was adjusted to 9-10 by theaddition of 1 M NaOH (aq, 1120 mL). The thick suspension was stirred for30 min and the solid filtered, washed with water (2×1300 mL) and pulleddry. Further drying in a vacuum oven at 45° C. yielded a white solid(390.9 g, 91%). Combined batches of this material (1098.1 g) weredissolved in DMSO (5490 mL) at 100-105° C. The solution was cooled to70-80° C. and polish filtered to a second vessel. The temperature of thesolution was adjusted to 75-80° C. and EtOH (6560 mL) was addeddrop-wise at 75-80° C. over 1 h (crystallisation occurred duringaddition). The suspension was stirred at 70° C. for 14 h before coolingto 18-25° C. at a rate of 10° C./h then stirred for 1 h. The solid wasfiltered, washed with ethanol (4×3660 mL) and pulled dry. Further dryingin a vacuum oven yielded the title compound as an off-white solid (870g). A suspension of (635.6 g) of this material in water (9534 mL)/MeCN(3432 mL) was acidified to pH 1 with 2 M aqHCl (1907 mL). After stirringat 18-25° C. for 1 h, the solid was filtered, washed with water (3180 mLthen 2×1990 mL) and pulled dry. The wet cake was suspended in water(9534 mL)/EtOH (3432 mL) and the pH adjusted to 9-10 (monitored with pHmeter) by the addition of 1 M aq NaOH (˜2 L). The suspension was stirredat 18-25° C. for 1 h maintaining the pH at 9-10 as required (using 1 Maq NaOH). The solid was filtered, washed with water (3150 mL then 2×1574mL) and pulled dry. Further drying in a vacuum oven at 45° C. yieldedthe title compound as white crystals (533.9 g). ¹H NMR (500 MHz,MeOH-d₄) δ 4.40 (s, 2H), 5.75 (s, 2H), 6.15 (d, 1H), 6.97 (d, 1H), 7.31(d, 1H), 7.34 (dd, 1H), 7.53 (d, 1H). MS (APCI+) m/z 321 [M+H]⁺.

LC indicated a purity of 98.4% with no single impurity >0.5%. KarlFischer titration indicated 1.19% water.

The solid residue was found to be crystalline by XRPD and a typicaldiffractogram is displayed in FIG. 5. Characteristic peak positions arelisted below.

XRPD pattern 2-Theta (°) 6.5 (m), 9.0 (m), 12.8 (vs), 16.8 (m), 18.0(s), 23.5 (s), 25.6 (s), 26.3 (w), 30.5 (w), 34.0 (w).

Example 81-{4-Chloro-2-[(methylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

A mixture of5-chloro-2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(see Example 6(e)) (1.00 g, 3.13 mmol) and methanamine (20 mL, 40.00mmol) was heated in a microwave oven at 100° C. for 20 min. The mixturewas diluted with MeOH and stirred at r.t. whereupon sodiumtetrahydroborate (0.95 g, 25 mmol) was added in portions during 5 min.After stirring at r.t. for 1 h, the mixture was heated to reflux for 2h. Another portion of sodium tetrahydroborate (0.47 g, 12.5 mmol) wasadded and the mixture was refluxed for additional 15 min. The solventwas removed by evaporation and to the residue was added water (20 mL)and an aq solution of HCl (1 M, 10 mL) to adjust the pH to 1. Themixture was cooled with an ice-bath and the formed precipitate wasfiltered off and washed with water (100 mL). The filtrate was cooledwith an ice-bath and and the pH adjusted to pH 9 using an aq NH₃solution (12%, 6 mL). A precipitate was isolated by filtration. Afterdrying in vacuum, there was obtained 700 mg (67%) of the desired productas a white solid. ¹H NMR (400 MHz, DMSO-d₆): δ 2.34 (d, 3H), 3.78 (s,2H), 5.72 (s, 2H), 6.04 (t, 1H), 6.66 (d, 1H), 7.16 (dd, 1H), 7.27 (d,1H), 7.41 (d, 1H). MS (APCI+) m/z 335 [M+H]⁺.

Example 91-(2-{[(Cyclobutylmethyl)amino]methyl}benzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(a) Ethyl3-{[2-(1,3-dioxolan-2-yl)benzyl]amino}-1H-pyrrole-2-carboxylate

A solution of ethyl 3-amino-1H-pyrrole-2-carboxylate hydrochloride (5.66g, 29.69 mmol) in EtOH (30 mL) was treated with DIPEA (6.22 mL, 35.63mmol) and stirred for 10 min before the addition of HOAc (4.08 mL, 71.25mmol) and sodium cyanoborohydride (2.80 g, 44.53 mmol). A solution of2-(1,3-dioxolan-2-yl)benzaldehyde (5.29 g, 29.69 mmol) in EtOH (20 mL)was then added dropwise over a period of 15 min. The resultantsuspension was stirred at r.t. overnight. The reaction mixture wasevaporated in vacuo and the residue treated with water (200 mL) andextracted with dichloromethane (3×150 mL). The organic solution wasfiltered through a silica gel column using a gradient of EtOAc andCH₂Cl₂ (0-100% EtOAc). There was obtained 12.63 g of the title compoundas a crude product.

(b) Ethyl3-{(benzoylcarbamothioyl)[2-(1,3-dioxolan-2-yl)benzyl]amino}-1H-pyrrole-2-carboxylate

Ethyl 3-{[2-(1,3-dioxolan-2-yl)benzyl]amino}-1H-pyrrole-2-carboxylate(12.63 g, 39.92 mmol) was suspended in CH₂Cl₂ (60 mL) and the suspensiontreated with DIPEA (7.09 mL, 39.92 mmol). The mixture was stirred for0.25 h at r.t. and then benzoyl isothiocyanate (5.37 mL, 39.92 mmol) wasadded. After stirring for 18 h, the solvent was removed in vacuo. Therewas obtained 24.8 g of a crude title compound that was used withoutpurification in the next step.

(c)1-[2-(1,3-Dioxolan-2-yl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

Ethyl3-{(benzoylcarbamothioyl)[2-(1,3-dioxolan-2-yl)benzyl]amino}-1H-pyrrole-2-carboxylate(24.8 g, 51.72 mmol) was dissolved in MeOH (100 mL) and the solutiontreated with sodium hydroxide (10.34 g, 258.6 mmol). The mixture washeated to gentle reflux and stirred for 3.5 h. After cooling, thesolvent was removed in vacuo. The residue was taken up in water,neutralised using HCl (2 M) and the mixture extracted with CH₂Cl₂ (3×50mL). The combined extracts were washed with water (2×30 mL), dried(MgSO₄), filtered and evaporated. The residue was stirred with Et₂O andthe precipitate was collected and dried under vacuum. There was obtained1.2 g (12.3% over 3 steps) of the title compound. MS (APCI+) m/z 330[M+H]⁺.

(d)2-[(4-Oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde

To a solution of1-[2-(1,3-dioxolan-2-yl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one(1.2 g, 3.64 mmol) was added a solution of TFA (5.0 mL, 64.90 mmol) inCH₂Cl₂ (30 mL) and the mixture was stirred over night. The reactionmixture was refluxed for 7 h and then concentrated under vacuum. Toluenewas added to co-evaporate the TFA. The dried crude was stirred with Et₂Oto triturate the product which was collected via filtration and driedunder vacuum. There was obtained 1.02 g (98%) of the title compound as asolid. MS (APCI+) m/z 286 [M+H]⁺.

(e)1-(2-{[(Cyclobutylmethyl)amino]methyl}benzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

A solution of2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(100 mg, 0.35 mmol), DIEA (0.184 mL, 1.05 mmol) andcyclobutylmethanamine (128 mg, 1.05 mmol) in dry NMP (3 mL) was stirredfor 60 min then treated with sodium borohydride (19.89 mg, 0.53 mmol)and stirred at r.t. for 30 min. The solution was adsorbed by gravityonto a 10 g SCX column preswollen in NMP and the column then washed withMeOH (100 mL). The crude product was eluted using a solution of NH₃ inMeOH (3 M, 50 mL). The solvent was removed in vacuo and the residue waspurified on a C8 column eluting with a gradient of MeOH in water (0.1%TFA). The product was slurried in dichloromethane (2 mL) to give 48 mg(38%) of the desire compound as a solid. ¹H NMR (400 MHz, DMSO-d₆): δ1.70-3.20 (m, 9H), 4.35 (m, 2H), 5.78 (s, 2H), 6.06 (m, 1H), 6.78 (d,1H), 7.29 (t, 1H), 7.35 (m, 2H), 7.54 (d, 1H), 8.8 (b, 2H). MS (APCI+)m/z 355 [M+H]⁺.

Example 101-{2-[(Cyclobutylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 49% yield starting from2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(100 mg, 0.35 mmol) and cyclobutanamine (249 mg, 3.50 mmol) using theprocedure described in Example 9. ¹H NMR (400 MHz, DMSO-d₆) δ 1.74-1.94(m, 2H), 2.17-2.30 (m, 4H), 3.88 (s, 1H), 4.26 (s, 2H), 5.78 (s, 2H),6.04 (t, 1H), 6.77 (d, 1H), 7.26-7.39 (m, 3H), 7.52 (dd, 1H), 9.09 (s,2H), 12.41 (s, 1H), 12.52 (s, 1H). MS (APCI+) m/z 341 [M+H]⁺.

Example 111-{2-[(Cyclopentylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 54% yield starting from2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(100 mg, 0.35 mmol) and cyclopentanamine (0.35 mL, 3.50 mmol) using theprocedure described in Example 9. ¹H NMR (400 MHz, DMSO-d₆): δ 1.40-2.80(m, 8H), 3.70 (m, 1H), 4.37 (m, 1H), 5.79 (s, 2H), 6.04 (t, 1H), 6.79(d, 1H), 7.20-7.40 (m, 3H), 7.54 (d, 1H) 8.85 (b, 2H). MS (APCI+) m/z355 [M+H]⁺.

Example 121-(2-{[(2-Methylpropyl)amino]methyl}benzyl)-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 71% yield starting from2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(100 mg, 0.35 mmol) and 2-methylpropan-1-amine (0.35 mL, 3.50 mmol)using the procedure described in Example 9. ¹H NMR (400 MHz, DMSO-d₆): δ1.00 (d, 6H), 2.05 (m, 1H), 2.95 (m, 2H), 4.40 (m, 2H), 5.79 (s, 1H),6.06 (dd, 1H), 6.78 (d, 1H), 7.28 (t, 1H), 7.36 (m, 2H), 7.58 (dd, 1H),8.78 (b, 2H). MS (APCI+) m/z 343 [M+H]⁺.

Example 131-{2-[(Propan-2-ylamino)methyl]benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

The title compound was obtained as a solid in 33% yield starting from2-[(4-oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]benzaldehyde(100 mg, 0.35 mmol) and 2-methylpropan-1-amine propan-2-amine (0.45 mL,5.61 mmol) using the procedure described in Example 9. ¹H NMR (400 MHz,DMSO-d₆): δ 1.36 (d, 6H), 3.55 (m, 1H), 4.39 (m, 2H), 5.79 (s, 1H), 6.05(d, 1H), 6.78 (d, 1H), 7.27 (t, 1H), 7.36 (m, 2H), 7.54 (dd, 1H), 8.76(b, 2H). MS (APCI+) m/z 329 [M+H]⁺.

Example 141-[2-(Aminomethyl)-4-(trifluoromethyl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

(a) 1-Bromo-2-(diethoxymethyl)-4-(trifluoromethyl)benzene

A solution of 2-bromo-5-(trifluoromethyl)benzaldehyde (0.60 mL, 3.95mmol), triethyl orthoformate (1.316 mL, 7.90 mmol) andtetrabutylammonium tribromide (0.019 g, 0.04 mmol) in EtOH (99.5%, 6 mL)was stirred at r.t. for 8 h. Additional triethyl orthoformate (1.32 mL,7.90 mmol) and tetrabutylammonium tribromide (0.019 g, 0.04 mmol) wereadded and the reaction mixture was stirred for additionally 15 h.

The solvent was removed under reduced pressure and to the residue wereadded an aq solution of sat. NaHCO₃ and EtOAc. The layers were separatedand the aq phase was extracted twice with EtOAc. The combined organiclayers were washed with brine, dried with a phase separator and thesolvent was removed under reduced pressure to result in 0.94 g (72%) ofthe title compound. ¹H NMR (500 MHz, CDCl₃): δ 1.27 (t, 6H), 3.58-3.73(m, 4H), 5.67 (s, 1H), 7.45 (dd, 1H), 7.69 (d, 1H), 7.93 (d, 1H).

(b) 2-(Diethoxymethyl)-4-(trifluoromethyl)benzaldehyde

Butyllithium (2.5 M in hexane, 15.47 mL, 38.67 mmol) was added dropwiseto a solution of 1-bromo-2-(diethoxymethyl)-4-(trifluoromethyl)benzene(11.5 g, 35.15 mmol) in THF (130 mL) at −78° C. under a nitrogenatmosphere and the resulting solution was stirred at −78° C. for 30 min.DMF (4.06 mL, 52.73 mmol) was added dropwise at −78° C. The reactionmixture was allowed to warm to r.t. and stirred for 2 h. An aq solutionof sat. NH₄Cl was added and the phases were separated. The aq layer wasextracted twice with EtOAc. The combined organic layers were washed withbrine, dried (phase separator) and the solvents were removed underreduced pressure. There was obtained 9.0 g (33%) of the title compound.

(c) Ethyl3-{[2-(diethoxymethyl)-4-(trifluoromethyl)benzyl]amino}-1H-pyrrole-2-carboxylate

Ethyl 3-amino-1H-pyrrole-2-carboxylate (5.02 g, 32.58 mmol) wasdissolved in EtOH (99.5%, 110 mL) and to the resultant solution wasadded DIPEA (5.67 mL, 32.58 mmol) followed by HOAc (3.73 mL, 65.16mmol). The reaction mixture was cooled to −10° C. and then sodiumcyanotrihydroborate (2.46 g, 39.09 mmol) was added.2-(Diethoxymethyl)-4-(trifluoromethyl)benzaldehyde (9 g, 32.58 mmol)dissolved in EtOH (99.5%, 10 mL) was then added slowly. The reactionmixture was stirred at 0° C. and then stirred for 16 h, during which thetemperature was allowed to increase to r.t. Water was added and themixture extracted with toluene. The aq phase was further extracted twicewith toluene and the combined organic layers were washed with brine,dried through a phase separator and the solvent was removed underreduced pressure. The product was purified by preparative HPLC using aC8 column and using a mixture comprising a gradient (50%-100%) MeCN inwater, MeCN and ammonium acetate buffer (0.1 M). After four injections,there was obtained 4.5 g (33%) of the title compound. ¹H NMR (500 MHz,CDCl₃): δ 1.25 (td, 4H), 1.34 (t, 3H), 3.51-3.7 (m, 5H), 4.31 (dd, 2H),4.57 (s, 2H), 5.60 (dd, 1H), 5.66 (s, 1H), 6.68 (s, 1H), 7.53 (d, 1H),7.58 (d, 1H), 7.85 (s, 1H), 8.09 (d, 1H). MS (APCI+) m/z 414 [M+H]⁺.

(d)1-[2-(Diethoxymethyl)-4-(trifluoromethyl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

Ethyl3-{[2-(diethoxymethyl)-4-(trifluoromethyl)benzyl]amino}-1H-pyrrole-2-carboxylate(4.3 g, 10.38 mmol) was dissolved in MeOH (40 mL) and to the resultantsolution was added benzoyl isothiocyanate (1.40 mL, 10.38 mmol). Thereaction mixture was stirred at r.t. for 15 min and then Cs₂CO₃ (7.27 g,22.31 mmol) was added. The mixture was stirred at 60° C. for 6 h andthen the solvent was removed under reduced pressure. Water anddichloromethane were added and the aq phase was further extracted tricewith CH₂Cl₂. The organic layers were combined and the solvent wasremoved under reduced pressure. The residue was triturated with Et₂O.The formed suspension was stirred for 4 h and the solid isolated byfiltration. The solids were washed with Et₂O to give 3.46 g (78%) of thetitle compound. ¹H NMR (500 MHz, DMSO-d₆): δ 1.22 (t, 6H), 3.55-3.72 (m,4H), 5.89 (s, 3H), 5.95 (s, 1H), 6.94 (d, 1H), 7.24 (s, 1H), 7.59 (d,1H), 7.83 (s, 1H), 12.38 (s, 2H). MS (APCI−) m/z 426 [M−H]⁻.

(e)2-[(4-Oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]-5-(trifluoromethyl)benzaldehyde

A mixture of TFA (2.90 mL, 39.07 mmol) and CH₂Cl₂ (12 mL) was cooled to0° C. and to the solution was added1-(2-(diethoxymethyl)-4-(trifluoromethyl)benzyl)-2-thioxo-2,3-dihydro-1H-pyrrolo[3,2-d]pyrimidin-4(5H)-one(1.67 g, 3.91 mmol). The ice-bath was removed and the mixture wasstirred at r.t. for 2.5 h. The resulting solid was filtered and washedwith CH₂Cl₂ to result in 1.31 g (95%) of the title compound. ¹H NMR (500MHz, DMSO-d₆): δ 6.09-6.16 (m, 3H), 7.08 (d, 1H), 7.31 (t, 1H), 7.89(dd, 1H), 8.41 (d, 1H), 10.34 (s, 1H), 12.44 (s, 1H), 12.52 (s, 1H). MS(APCI+) m/z 352 [M−H]⁻.

(f)1-[2-(Aminomethyl)-4-(trifluoromethyl)benzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

2-[(4-Oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]-5-(trifluoromethyl)benzaldehyde(195 mg, 0.55 mmol) was added to a mixture of hydroxylaminehydrochloride (42 mg, 0.61 mmol) in HOAc (80%, 4 mL). The mixture wasstirred at r.t. for 1 h and zinc (181 mg, 2.76 mmol) was added. Afterstirring at 60° C. for 1.5 h, the mixture was cooled and the pH adjustedto 12 with aq NaOH (1 M). The resulting precipitate was collected byfiltration. The product was purified by preparative HPLC on a C8 columnusing a gradient of 5-45% MeCN in water, MeCN and FA (95/5/0.2). Therewas obtained 70 mg (36%) of the desired compound. ¹H NMR (500 MHz,DMSO-d₆): δ 4.37 (s, 2H), 5.81 (s, 2H), 6.11 (s, 1H), 6.93 (d, 1H), 7.36(s, 1H), 7.63 (d, 1H), 7.89 (s, 1H), 8.36 (s, 2H), 12.47 (s, 1H), 12.56(s, 1H).

Example 151-{2-[(Methylamino)methyl]-4-(trifluoromethyl)benzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

2-[(4-Oxo-2-thioxo-2,3,4,5-tetrahydro-1H-pyrrolo[3,2-d]pyrimidin-1-yl)methyl]-5-(trifluoromethyl)benzaldehyde(214 mg, 0.61 mmol) and methanamine (2 M in MeOH, 3.03 mL, 6.06 mmol)were dissolved in MeOH (5 mL) and the resulting solution was transferredto a microwave vial. The reaction mixture was heated at 100° C. for 5min and then diluted with THF (5 mL). Sodium tetrahydroborate (183 mg,4.85 mmol) was added in small portions during 2 min. The reactionmixture was stirred at r.t. for 30 min and then quenched by the additionof water. The solvents were evaporated and the crude product waspurified by preparative HPLC on a C18 column using a gradient of 15-55%MeCN in water, MeCN and 0.1 M NH₄OAc buffer (95/5/0.2), then re-purifiedusing a gradient of 0-30% MeCN in water, MeCN and FA (95/5/0.2). Therewas obtained 62 mg (28%) of the title compound. ¹H NMR (500 MHz,DMSO-d₆) δ 2.42 (s, 3H), 3.94 (s, 2H), 5.85 (s, 2H), 6.10 (d, 1H), 6.88(d, 1H), 7.32 (d, 1H), 7.51 (d, 1H), 7.76 (s, 1H), 8.19 (s, 1H). MS(APCI+) m/z 369 [M+H]⁺.

What is claimed is: 1-17. (canceled)
 18. A method of identifying apatient suitable for MPO inhibitor treatment encompassing themeasurement of plasma urate levels.
 19. A method according to claim 18,wherein the MPO inhibitor is1-{2-[(1R)-1-aminoethyl]-4-chlorobenzyl}-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one

or a pharmaceutically acceptable salt thereof.
 20. A method according toclaim 18, wherein the MPO inhibitor is1-[2-(aminomethyl)-4-chlorobenzyl]-2-thioxo-1,2,3,5-tetrahydro-4H-pyrrolo[3,2-d]pyrimidin-4-one:

or a pharmaceutically acceptable salt thereof.